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Lipoprotein(a) (Lp(a)) has garnered increasing attention as a significant contributor to the pathogenesis of aortic stenosis (AS), prompting a focused investigation into innovative pharmacological strategies to target this lipoprotein and its associated risks. Despite its recognized role in AS progression, Lp(a) often remains overlooked in clinical assessments, mirroring the broader challenges observed in holistic disease management. This review delves into the mechanistic intricacies of Lp(a) involvement in AS pathophysiology and its potential as a therapeutic target. Drawing parallels with the imperative for healthcare providers to proactively engage with patients regarding treatment regimens, this review underscores the essential role of cardiologists and physicians in recognizing and addressing Lp(a) as a modifiable risk factor in AS management. Furthermore, it explores promising avenues of novel drug approaches, including emerging pharmacotherapies and targeted interventions, aimed at modulating Lp(a) levels and attenuating AS progression. By navigating the complexities of Lp(a) modulation and its implications for AS management, this review aims to bridge critical gaps in understanding and clinical practice, ultimately optimizing treatment strategies and improving patient outcomes in the realm of AS therapeutics.

IntroductionSeagrass sediments are important ‘blue carbon’ reservoirs which store climatically significant quantities of organic carbon (Corg) at the global scale. Seagrass meadows that overly these sediments also provide a range of critical ecosystem services including shoreline stabilization, storm surge protection, and fisheries nursery grounds. However, the controls over accumulation and the sources of organic C to these sediments beds are highly variable and poorly understood with the relative importance of hydrodynamic setting, species composition and canopy density being unclear.MethodsHere we address these questions using the first observation-based estimates of Corg stocks and provenance on Turneffe Atoll, Belize, made via remotely-sensed habitat extent, local Corg data and isotopic data. Sedimentary Corg was highest in sediments underlying the most sheltered meadows and decreased with increasing exposure to wind and wave energy with the seagrass meadows in the central lagoon containing an extensive deposit of mangrove derived organic carbon, stabilized and protected by the overlying seagrass meadow.ResultsThe influence of species composition appeared weak with the ubiquitous species T. testudinum occurring across a wide range of hydrodynamic regimes ranging from the most sheltered to the most energetic and being associated with a wide range of sedimentary organic C concentrations. Importantly from the perspective of remote sensing, org C concentrations were unrelated to canopy density. We hypothesize that this decoupling of organic C concentration from seagrass canopy cover reflects a much longer timescale for carbon storage in the sediments than the lifespan of the seagrass plants themselves and/or a substantial non seagrass derived organic C burden in seagrass sediments. Overall, we conservatively estimate that the top 30cm of sediments underlying the seagrass meadows overlying carbonate sediments on the atoll exterior store 0.58 x 106 Mg Corg, most of which is seagrass-derived, whilst the sediments underlying the meadows within the central lagoon store an additional 1.28 x 106 Mg Corg. When the maximum possible extent of seagrass is considered, this estimate increases to 3.54 x 106 Mg Corg. Substantial Corg stocks extending >1m depth were observed across all sites, and so these inventories are considered conservative.DiscussionA preliminary ‘cost of loss’ for sedimentary Corg in the top 30 cm of Turneffe Atoll’s seagrass meadows, based on a carbon trading value of €60 tCO2 (eq), is estimated at €42 million for the outer atoll, increasing to €136 million when the mangrove-derived sediments of the central atoll are considered and €260 million when turbid areas are assumed to contain seagrass.

This article provides a detailed analysis of non-invasive techniques for the prediction and diagnosis of faults in internal combustion engines, focusing on the application of the Proknow-C and Methodi Ordinatio systematic review methods. Initially, the relevance of these techniques in promoting energy sustainability and mitigating greenhouse gas emissions is discussed, aligning with the Sustainable Development Goals (SDGs) of Agenda 2030 and the Paris Agreement. The systematic review conducted in the subsequent sections offers a comprehensive mapping of the state of the art, highlighting the effectiveness of combining these methods in categorizing and systematizing relevant scientific literature. The results reveal significant advancements in the use of artificial intelligence (AI) and digital signal processors (DSP) to improve fault diagnosis, in addition to highlighting the crucial role of non-invasive techniques such as the digital twin in minimizing interference in monitored systems. Finally, concluding remarks point towards future research directions, emphasizing the need to develop the integration of AI algorithms with digital twins for internal combustion engines and identify gaps for further improvements in fault diagnosis and prediction techniques.

This manuscript investigates the atmospheric corrosion of carbon steel in Puerto Lopez, a coastal region in Manabí Province, Ecuador. For the study, six outdoor exposure sites (OES) were strategically placed at different distances from the coast to evaluate the impact of meteorological factors on the chloride deposition rate (Cl−DR) and how proximity to the coast could influence atmospheric corrosivity to carbon steel. It identified a critical threshold for the monthly average wind speed that escalates Cl−DR, noted as one of the lowest globally. The findings revealed a medium corrosivity category (C3) for carbon steel in the inland OES, suggesting the significant role of high relative humidity (RH) typical of the area in possibly reducing Cl−DR through saline dissolution. Moreover, the interaction between high RH and Cl−DR could markedly diminish oxygen's solubility in water collected in oxide layer interstices and on the carbon steel surfaces, potentially affecting the cathodic oxygen reaction. Nonetheless, the study confirms the continuing influence of Cl−DR on the atmospheric corrosion of carbon steel. Predictive corrosivity categories for carbon steel in this coastal environment span from two to twenty years across the OES, underlining the critical need for understanding and mitigating corrosion in similar settings.

This work was conducted over three-year monitoring seasons of three almond cultivars (Guara, Marta, and Lauranne) subjected to deficit irrigation in combination with cover crops in a Mediterranean semiarid area (SW, Spain). Four water–soil treatments were evaluated based on the conjunction of two irrigation strategies: fully irrigated (FI), covering 100% of the ETC, and regulated deficit irrigation (RDI), with two soil-management systems: bare soil (BS) and cover crop based on a mixture of vetch (Vicia sativa L.) and oat (Avena sativa L.) (CC). Throughout the study period in trees, the yield, the stem water potential (Ψstem), leaf nutrient content (N, P, K, Ca, Mg, Na, Fe, Zn, Mn, and Cu) in soils, organic carbon, microbial biomass, fluoresceine diacetate, and enzymatic activities (dehydrogenase, protease, β-glucosidase, and alkaline phosphatase) were determined. In addition, the dry matter and carbon fixation by plant covers were evaluated. For Guara and Lauranne, yield reductions (22 and 26%, respectively) were found for water-stressed (RDI-CC) plots with respect to non-stressed combination (FI-CC) plots, contrasting with cv. Marta, without a significant impact on productivity in all combinations. That is, the RDI (~3.000 m3 ha−1) strategy enabled acceptable productivity, offering promising possibilities for cultivation performance under water-scarcity scenarios. Important differences in Ψstem could be observed and ascribed to irrigation strategies, especially for Guara and Lauranne, but without significant effects due to the soil-management systems applied. No differences were observed in the tree nutritional status due to the presence or absence of CC; however, its presence increased the fixation of atmospheric carbon, which was not the case under BS conditions. Additionally, CC significantly fostered the microbial processes and enzymatic activities, particularly in upper soil layers (0–10 cm) and with plenty of water supply in FI-CC plots and to a lesser extent in RDI-CC plots, which could encourage prominent aspects for soil quality and health restoration. Thus, the cover crop is congruent with RDI to facilitate soil functionality and water savings in a changing climate, contributing to resilient farming systems in the Mediterranean environment.

The present work proposes a new model based on a convolutional neural network (CNN) to retrieve solar shortwave (SW) irradiance via the estimation of the cloud modification factor (CMF) from daytime sky images captured by all-sky cameras; this model is named CNN-CMF. To this end, a total of 237,669 sky images paired with SW irradiance measurements obtained by using pyranometers were selected at the following three sites: Valladolid and Izaña, Spain, and Lindenberg, Germany. This dataset was randomly split into training and testing sets, with the latter excluded from the training model in order to validate it using the same locations. Subsequently, the test dataset was compared with the corresponding SW irradiance measurements obtained by the pyranometers in scatter density plots. The linear fit shows a high determination coefficient (R2) of 0.99. Statistical analyses based on the mean bias error (MBE) values and the standard deviation (SD) of the SW irradiance differences yield results close to −2% and 9%, respectively. The MBE indicates a slight underestimation of the CNN-CMF model compared to the measurement values. After its validation, model performance was evaluated at the Antarctic station of Marambio (Argentina), a location not used in the training process. A similar comparison between the model-predicted SW irradiance and pyranometer measurements yielded R2=0.95, with an MBE of around 2% and an SD of approximately 26%. Although the precision provided by the SD at the Marambio station is lower, the MBE shows that the model’s accuracy is similar to previous results but with a slight overestimation of the SW irradiance. Finally, the determination coefficient improved to 0.99, and the MBE and SD are about 3% and 11%, respectively, when the CNN-CMF model is used to estimate daily SW irradiation values.

This work presents an electrical measurement dataset from a split-system air conditioner in normal operating conditions and with specific faults, such as incrustation in the condenser and evaporator air inlet with different levels of blocking, which often occurs in this type of equipment. We also added compressor capacitor degradation, which is a very common fault in this type of equipment, although it is scarcely addressed in research. The data were obtained through a non-invasive current sensor and a grain-oriented voltage sensor containing the values of the current and voltage of equipment that was installed in the field and tested at different levels for these fault conditions. This work not only explains how the entire data collection process was carried out but also presents two examples of fast Fourier transform (FFT) applications for the detection and diagnosis of faults through the electrical measurements analyzed in our studies, which had good effectiveness.

Se realizó un estudio basado en la evaluación de la corrosividad de la atmósfera sobre el acero al carbono en una zona costera del cantón de Manta en Manabí, Ecuador. Ocho sitios de exposición fueron seleccionados a diferentes distancias desde la línea costera. En cada sitio de exposición se colocaron soportes de madera con tres captadores de paño seco para la determinación mensual de la deposición de las sales de iones cloruro y seis probetas metálicas de acero al carbono de dimensiones estandarizadas. Tres probetas metálicas para la medición mensual y anual de la velocidad de corrosión atmosférica para cada tiempo de exposición respectivamente durante un año de estudio. Los valores promedio mensuales de humedad relativa, temperatura y viento fueron obtenidos de una estación meteorológica ubicaba cerca de la zona de estudio. Los resultados obtenidos a partir de la descripción típica del ambiente agresivo costero de la atmósfera y los demostrados en cuanto al comportamiento de la velocidad de corrosión mensual y los factores influyentes, así como las categorías de corrosividad de la atmósfera determinadas a diferentes distancias desde la línea costera, pueden ser tomados como criterios por durabilidad, antes de proceder con las labores de diseño, construcción, mantenimiento y reparación de las estructuras en la zona costera de estudio. Se demostró una diferencia entre las dos variantes de evaluación de la corrosividad de la atmósfera, es decir, entre la estimación a partir de la descripción típica del ambiente agresivo costero de la atmósfera en la zona de estudio.

In this work, a series of durability requirements are proposed for the construction of long-service-life reinforced concrete (RC) structures in a coastal environment with extreme atmospheric corrosivity. RC specimens were exposed in a coastal outdoor site in Cuba for three years. Carbon steel corrosion evaluation revealed an annual average atmospheric corrosion rate over the maximum limit established (ISO 9223:2012) for extreme (CX) atmospheric corrosivity. The service life of the RC structures, considered as the sum of the time-to-corrosion-initiation and time-to-corrosion-induced concrete cracking, was determined as a function of durability requirements. The most important durability requirements to achieve a long service life (>70 years) in RC structures subjected to a CX corrosivity category were defined as follows: water/cement ratio, compressive strength, percentage of effective capillary porosity, and concrete cover thickness. Under these hostile environments, the expansion of the corrosion products formed on the reinforcement steel and the induced cracking of the concrete could be attributed partially to the formation of the akaganeite phase in reinforcement steel, which revealed a different morphology compared to the akaganeite typically formed in bare carbon steels.

Background Cerebral embolic protection devices (CEPD) capture embolic material in an attempt to reduce ischemic brain injury during transcatheter aortic valve replacement. Prior reports have indicated mixed results regarding the benefits of these devices. With new data emerging, we performed an updated meta‐analysis examining the effect of CEPD during transcatheter aortic valve replacement on various clinical, neurological, and safety parameters. Methods and Results A comprehensive review of electronic databases was performed comparing CEPD and no‐CEPD in transcatheter aortic valve replacement. Primary clinical outcome was all‐cause stroke. Secondary clinical outcomes were disabling stroke and all‐cause mortality. Neurological outcomes included worsening of the National Institutes of Health Stroke Scale score, Montreal Cognitive Assessment score from baseline at discharge, presence of new ischemic lesions, and total lesion volume on neuroimaging. Safety outcomes included major or minor vascular complications and stage 2 or 3 acute kidney injury. Seven randomized controlled trials with 4016 patients met the inclusion criteria. There was no statistically significant difference in the primary clinical outcome of all‐cause stroke; secondary clinical outcomes of disabling stroke, all‐cause mortality, neurological outcomes of National Institutes of Health Stroke Scale score worsening, Montreal Cognitive Assessment worsening, presence of new ischemic lesions, or total lesion volume on diffusion‐weighted magnetic resonance imaging between CEPD versus control groups. There was no statistically significant difference in major or minor vascular complications or stage 2 or 3 acute kidney injury between the groups. Conclusions The use of CEPD in transcatheter aortic valve replacement was not associated with a statistically significant reduction in the risk of clinical, neurological, and safety outcomes.

This work introduces CAECENET, a new system capable of automatically retrieving columnar and vertically-resolved aerosol properties running the GRASP (Generalized Retrieval of Atmosphere and Surface Properties) algorithm using sun-sky photometer (aerosol optical depth, AOD; and sky radiance measurements) and ceilometer (range corrected signal; RCS) data as input. This method, so called GRASPpac, is implemented in CAECENET, which assimilates sun-sky photometers data from CÆLIS database and ceilometer data from ICENET database (Iberian Ceilometer Network). CAECENET allows for continuous and near-real-time monitoring of both vertical and columnar aerosol properties. The main characteristics and workflow of CAECENET are explained in detail. This work also explores the potential of CAECENET to monitor and analyze the evolution of transported aerosol events on a regional scale by means of the distribution of CAECENET stations across the Iberian Peninsula. As an example, this paper analyzes, using the CAECENET products, the case of a Saharan dust outbreak that occurred between the 3rd and 5th of October 2022. This was an intense event, with AOD at 440 nm values around 0.5 in Madrid and Valladolid, and reaching 1.55 in Granada. Transport from the Canadian wildfires at the end of June 2023 is also studied. Despite the long-range transport of the smoke particles in this event, measured volume concentrations reached and surpassed 80 μm3/cm3 in some stations. The results obtained point to the utility of this CAECENET tool for analyzing changes in the height and speed of the event propagation, in the aerosol concentration, and how this affects the optical properties.

Let $ f:V(G)\rightarrow \{0, 1, 2\} $ be a function defined from a connected graph $ G $. Let $ W_i = \{x\in V(G): f(x) = i\} $ for every $ i\in \{0, 1, 2\} $. The function $ f $ is called a total Italian dominating function on $ G $ if $ \sum_{v\in N(x)}f(v)\geq 2 $ for every vertex $ x\in W_0 $ and if $ \sum_{v\in N(x)}f(v)\geq 1 $ for every vertex $ x\in W_1\cup W_2 $. The total Italian domination number of $ G $, denoted by $ \gamma_{tI}(G) $, is the minimum weight $ \omega(f) = \sum_{x\in V(G)}f(x) $ among all total Italian dominating functions $ f $ on $ G $. In this paper, we provide new lower and upper bounds on the total Italian domination number of trees. In particular, we show that if $ T $ is a tree of order $ n(T)\geq 2 $, then the following inequality chains are satisfied. (ⅰ) $ 2\gamma(T)\leq \gamma_{tI}(T)\leq n(T)-\gamma(T)+s(T) $, (ⅱ) $ \frac{n(T)+\gamma(T)+s(T)-l(T)+1}{2}\leq \gamma_{tI}(T)\leq \frac{n(T)+\gamma(T)+l(T)}{2}, $ where $ \gamma(T) $, $ s(T) $ and $ l(T) $ represent the classical domination number, the number of support vertices and the number of leaves of $ T $, respectively. The upper bounds are derived from results obtained for the double domination number of a tree.

The durability performance of construction-manufacturing materials from the People's Republic of China will be studied consideringthe impact of the aggressive coastal environment of Cuba's atmosphere.Research studies between two countries, one characterized by a very high production and commercialization of metallic materials for construction-manufacturing industry as China, and the other by present a very high impact of the aggressive coastal environment of the atmosphere on the materials as Cuba, were not found.The research studies carried out evaluated the impact of the aggressive coastal environment of the atmosphereindependently on their own materials. Thermoplastic and thermosetting polymeric materialswere not considered.The requirements by durability that are intended to be defined in the construction-manufacturing materials, will guarantee a higher long project service to all the infrastructure to be built or manufactured, mainly in any coastal zone in China and worldwide. A very significant economic benefit for developing countries is expected. In this way, the infrastructure exposed to the impact of the coastal atmospheric environment in any coastal zone worldwide, will almostnever reach its residual useful life.Cuba, as an island with a tropical coastal climate, in addition to the high relative humidity and deposition of chloride ion salts in the form of saline solution, is an ideal country to carry out these studies.A new corrosivity category of the atmosphere higher than extreme(>CX) for carbon steelin a coastal zones with high construction potentialwas reported.

El presente trabajo busca describir los fundamentos teóricos del modelo de Ciclo de Vida del Área Turística (CVAT) de Butler. Por ello, desde una revisión documental, se analiza el interés de diseñar un modelo de CVAT, su actualización para continuar vigente, y las críticas que posicionan a su autor como protagonista en la evolución de destinos turísticos. Se concluye que aplicar un modelo de hace 42 años conlleva a plantearse el diseño de otras propuestas de evaluación competitiva enfocadas a la oferta turística actual, lejos de criterios cuantitativos como la ocupación hotelera o número de llegadas.

The recovery and re-calibration of a dataset of vertical aerosol extinction profiles of the 1963/64 stratospheric aerosol layer measured by a searchlight at 32° N in New Mexico, US, is reported. The recovered dataset consists of 105 aerosol extinction profiles at 550 nm that cover the period from December 1963 to December 1964. It is a unique record of the portion of the aerosol cloud from the March 1963 Agung volcanic eruption that was transported into the Northern Hemisphere subtropics. The data-recovery methodology involved re-digitizing the 105 original aerosol extinction profiles from individual Figures within a research report, followed by the re-calibration. It involves inverting the original equation used to compute the aerosol extinction profile to retrieve the corresponding normalized detector response profile. The re-calibration of the original aerosol extinction profiles used Rayleigh extinction profiles calculated from local soundings. Rayleigh and aerosol slant transmission corrections are applied using the MODTRAN code in transmission mode. Also, a best-estimate aerosol phase function was calculated from observations and applied to the entire column. The tropospheric aerosol phase function from an AERONET station in the vicinity of the searchlight location was applied between 2.76 to 11.7 km. The stratospheric phase function, applied for a 12.2 to 35.2 km altitude range, is calculated from particle-size distributions measured by a high-altitude aircraft in the vicinity of the searchlight in early 1964. The original error estimate was updated considering unaccounted errors. Both the re-calibrated aerosol extinction profiles and the re-calibrated stratospheric aerosol optical depth magnitudes showed higher magnitudes than the original aerosol extinction profiles and the original stratospheric aerosol optical depth, respectively. However, the magnitudes of the re-calibrated variables show a reasonable agreement with other contemporary observations. The re-calibrated stratospheric aerosol optical depth demonstrated its consistency with the tropics-to-pole decreasing trend, associated with the major volcanic eruption stratospheric aerosol pattern when compared to the time-coincident stratospheric aerosol optical depth lidar observations at Lexington at 42° N.

Three-phase induction motors are widely used in various industrial sectors and are responsible for a significant portion of the total electrical energy consumed. To ensure their efficient operation, it is necessary to apply control systems with specific algorithms able to estimate rotation speed accurately and with an adequate response time. However, the angular speed sensors used in induction motors are generally expensive and unreliable, and they may be unsuitable for use in hostile environments. This paper presents an algorithm for speed estimation in three-phase induction motors using the chaotic variable of maximum density. The technique used in this work analyzes the current signals from the motor power supply without invasive sensors on its structure. The results show that speed estimation is achieved with a response time lower than that obtained by classical techniques based on the Fourier Transform. This technique allows for the provision of motor shaft speed values when operated under variable load.

Let G be a nontrivial connected graph. For a set D⊆V(G), we define D¯=V(G)∖D. The set D is a total outer-independent dominating set of G if |N(v)∩D|≥1 for every vertex v∈V(G) and D¯ is an independent set of G. Moreover, D is a double outer-independent dominating set of G if |N[v]∩D|≥2 for every vertex v∈V(G) and D¯ is an independent set of G. In addition, D is a 2-outer-independent dominating set of G if |N(v)∩D|≥2 for every vertex v∈D¯ and D¯ is an independent set of G. The total, double or 2-outer-independent domination number of G, denoted by γtoi(G), γ×2oi(G) or γ2oi(G), is the minimum cardinality among all total, double or 2-outer-independent dominating sets of G, respectively. In this paper, we first show that for any cactus graph G of order n(G)≥4 with k(G) cycles, γ2oi(G)≤n(G)+l(G)2+k(G), γtoi(G)≤2n(G)−l(G)+s(G)3+k(G) and γ×2oi(G)≤2n(G)+l(G)+s(G)3+k(G), where l(G) and s(G) represent the number of leaves and the number of support vertices of G, respectively. These previous bounds extend three known results given for trees. In addition, we characterize the trees T with γ×2oi(T)=γtoi(T). Moreover, we show that γ2oi(T)≥n(T)+l(T)−s(T)+12 for any tree T with n(T)≥3. Finally, we give a constructive characterization of the trees T that satisfy the equality above.

Let $ G $ be a nontrivial graph and $ k\geq 1 $ an integer. Given a vector of nonnegative integers $ w = (w_0, \ldots, w_k) $, a function $ f: V(G)\rightarrow \{0, \ldots, k\} $ is a $ w $-dominating function on $ G $ if $ f(N(v))\geq w_i $ for every $ v\in V(G) $ such that $ f(v) = i $. The $ w $-domination number of $ G $, denoted by $ \gamma_{w}(G) $, is the minimum weight $ \omega(f) = \sum_{v\in V(G)}f(v) $ among all $ w $-dominating functions on $ G $. In particular, the $ \{2\} $-domination number of a graph $ G $ is defined as $ \gamma_{\{2\}}(G) = \gamma_{(2, 1, 0)}(G) $. In this paper we continue with the study of the $ \{2\} $-domination number of graphs. In particular, we obtain new tight bounds on this parameter and provide closed formulas for some specific families of graphs.

Aerosol optical depth (AOD) at night-time has become a hot topic in recent years due to the development of new instruments recording accurate ground-based lunar irradiance measurements, and the development of calibration methods and extraterrestrial irradiance models adapted to lunar photometry. This study uses all daytime and night-time AOD data available at Valladolid (Spain) from October 2016 to March 2022 in order to analyze its behavior and the added contribution of night data. The annual, monthly and daily AOD evolution is studied comparing daytime and night-time values and checking the correlation between them. For this purpose, the daily averages are computed, showing an annual pattern, with low AOD values throughout the year (mean value of AOD at 440 nm: 0.122), where winter months have the lower and summer the higher values, as observed in previous studies. All these AOD values are modulated by frequent desert dust events over the Iberian Peninsula, with a strong influence on daily and monthly mean values in February and March, where the strongest desert outbreaks occurred. The added new data confirm these results and the good correlation between daytime and night-time data. Also, a complete daily evolution is shown, observing that AOD and Ångström exponent (AE) mean values vary by only ±0.02 in 24 h, with a maximum value at 06:00 UTC and minimum at 18:00 UTC for both parameters.

Neste trabalho é apresentado um estudo sobre a detecção de falhas na pista externa dos rolamentos de um motor de indução trifásico, utilizando-se a análise de variáveis mecânicas (vibração e emissão acústica) e elétricas (eficiência energética). Especificamente, é proposta a avaliação da expressividade dos sinais na presença da avaria, aplicando-se, como ferramentas de análise para a vibração e a emissão acústica, as transformadas de Fourier e Wavelet. A estimação da eficiência energética, a partir da medição das tensões e correntes estatóricas, é sugerida como técnica alternativa para detecção da avaria. Resultados experimentais são apresentados para observação das estratégias sugeridas, avaliando-se a credibilidade da detecção da avaria com motor funcionando na rede sem carga, com carga estática (vibração e emissão acústica) e dinâmica (eficiência energética).

Coral reefs are highly diverse ecosystems that provide many goods and ecosystem services globally. Coral reef ecosystems are also threatened by environmental stressors from anthropogenic sources and shifting climates. The United Nations Sustainable Development Goal 14 (“Life Below Water”) addresses the need to conserve and sustainably use the ocean, seas, and marine ecosystems, including reef systems. Belize’s coral reef system is the second largest in the world, providing sources of income to Belizeans through tourism and fisheries as well as coastline protection. In order to conserve their marine ecosystems, Belize has a network of Marine Protected Areas (MPAs) throughout their coastal waters. Using Aqua MODIS satellite imagery from 2002 to 2022, Google Earth Engine, and RStudio, we present a workflow to calculate stress days on MPAs and a coral vulnerability index based on sea surface temperature (SST) and Kd (490), a proxy of water clarity. The Corozal Bay, Swallow Caye, Port Honduras, and South Water Caye MPAs had the highest percentages of stress days and coral vulnerability stress index score based on these two parameters among the 24 MPAs analyzed. Additionally, SST in the warmest month of the year in Belize were seen to increase across all MPAs from 2002 to 2022 (p < 0.01). This GEE toolkit provides a straightforward and accessible tool to help governments monitor both water quality and risks to coral reefs in accordance with SDG 14.

Let $ G $ be a graph with vertex set $ V(G) $. A function $ f:V(G)\rightarrow \{0, 1, 2\} $ is a Roman dominating function on $ G $ if every vertex $ v\in V(G) $ for which $ f(v) = 0 $ is adjacent to at least one vertex $ u\in V(G) $ such that $ f(u) = 2 $. The Roman domination number of $ G $ is the minimum weight $ \omega(f) = \sum_{x\in V(G)}f(x) $ among all Roman dominating functions $ f $ on $ G $. In this article we study the Roman domination number of direct product graphs and rooted product graphs. Specifically, we give several tight lower and upper bounds for the Roman domination number of direct product graphs involving some parameters of the factors, which include the domination, (total) Roman domination, and packing numbers among others. On the other hand, we prove that the Roman domination number of rooted product graphs can attain only three possible values, which depend on the order, the domination number, and the Roman domination number of the factors in the product. In addition, theoretical characterizations of the classes of rooted product graphs achieving each of these three possible values are given.

Las graves consecuencias que han tenido los accidentes ocurridos en instalaciones industriales o de servicios en los últimos años (fugas de sustancias tóxicas o inflamables, incendios y explosiones), establecen muy claramente que las personas, los bienes materiales y del medio ambiente que se encuentran próximos a un establecimiento en el que se utilizan, procesan, transportan o almacenan sustancias peligrosas, están sometidos a riesgos de accidentes mayores. El aspecto más importante es decidir qué tipo y nivel de riesgos se está dispuesto a admitir en contrapartida a los beneficios económicos y sociales que suponen dichas instalaciones, para lo cual se requiere, en primer lugar, identificar y evaluar los riesgos que las mismas representan para los elementos vulnerables ubicados en su entorno interior y exterior, y a partir de ello, definir las medidas de protección (de seguridad) preventivas y de mitigación que deben ser implementadas o reforzadas para que los niveles de riesgos se correspondan con los aceptados por la sociedad. El objetivo de este trabajo consiste en describir las principales características y limitaciones de los métodos de estudio predictivos más utilizados en cualquiera de las etapas de vida de la instalación que se estudia: diseño, construcción, modificación u operación. Se recomienda no dejar de utilizar en los estudios de riesgos, el método cualitativo HAZOP en procesos de cualquier nivel de complejidad, el método cuantitativo ACAF para procesos complejos y el método Bow-Tie cuando se centra el análisis en determinar la eficiencia e insuficiencia de las barreras de control.

En este trabajo, se resume una serie de conceptos básicos establecidos en la normativa de la especialidad de corrosión atmosférica (Normas ISO 9223:2012, ISO 9225:2012 e ISO 9266:2012). Los conceptos, son tenidos en cuenta a la hora de realizar un estudio de corrosión atmosférica o de agresividad corrosiva de la atmósfera para los materiales metálicos más usados en la industria de la construcción (acero al carbono, cinc, cobre y aluminio). Se describen algunas experiencias obtenidas que no son recogidas en la normativa de la especialidad, derivadas de los últimos estudios realizados en el clima tropical costero de Cuba. De esta forma se indica la necesidad de ejecutar siempre que sea posible, la primera variante para estimación de la agresividad corrosiva de la atmósfera basada en la descripción típica del ambiente atmosférico de conjunto con la tercera variante, fundamentada en la determinación de la medida directa de la velocidad de corrosión anual en probetas de dimensiones estandarizadas. Para ciertas condiciones descritas, ha existido una gran diferencia entre la estimación, haciendo uso de los valores indirectos anuales de velocidad de corrosión determinados por las funciones dosis/respuestas como segunda variante y la tercera variante de determinación de la agresividad corrosiva de la atmósfera para el acero al carbono y el acero galvanizado.

This paper presents a comparison of traditional thermal and chemical reduction methods with more recent ionizing radiation reduction via gamma rays and electron beams (e-beams). For GO, all synthesis protocols were adapted to increase production scale and are a contribution of this work. The typical Raman D-band of the GO was prominent (ID/IG ratio increased sixfold). When comparing the GO reduction techniques, dramatic differences in efficiency and GO particle characteristics were observed. Although thermal and chemical reduction are effective reduction methods, as shown through the use of FTIR spectroscopy and the C/O ratio from EDS chemical analysis, the thermal process renders great weight losses, whereas chemical processing may involve the use of hazardous chemical compounds. On the other hand, comparing the gamma rays and e-beam for 80 kGy, the Raman spectra and chemical analysis suggested that the e-beam caused a greater GO reduction: C/O ratio from EDS of 5.4 and 4.1, respectively. In addition to being fast and effective, ionizing radiation reduction processes allow easier control of the reduction degree by adjusting the radiation dose. When the dose increased from 40 to 80 kGy, the Raman spectra and EDS showed that the ID/IG and C/O ratios increased by 15 and 116%, respectively.

Introdução: A pessoa com doença crónica é desafiada a um continuum de adaptação à condição nova de saúde-doença. O défice de conhecimentos é uma barreira à incorporação de regimes terapêuticos, muitas vezes complexos, no seu quotidiano, assumindo o enfermeiro um papel facilitador do processo de transição. Objetivo: Avaliar os conhecimentos sobre a patologia nas pessoas com DII. Métodos: Estudo descritivo, correlacional e transversal, com abordagem quantitativa e amostra por conveniência. Como método de recolha de dados foi utilizado um inventário intitulado como “Inflammatory Bowel disease knowledge (IBD-KNOW)”, após tradução e adaptação para português. A análise dos dados foi realizada através do sistema operativo SPSS® versão 23. Resultados: A taxa média de respostas corretas ao IBD-KNOW foi de 57,1%. Nas dimensões “reprodução“ e “função” obtiveram-se os valores mais baixos de respostas corretas, respetivamente 25,4% e 32,4%. Verificou-se uma correlação positiva forte entre o conhecimento da DII e a idade de diagnóstico (r=0,717, p0,7). Conclusão: A maioria dos doentes não demonstra conhecimentos sobre a DII, nem evidencia comportamentos de adesão. Torna-se premente capacitar para o autocuidado terapêutico com a implementação da Consulta de Enfermagem.

Entre los accidentes de origen tecnológico, ocupan un importante lugar los denominados accidentes mayores, o sea los derrames (líquidos) o escapes (gases) de sustancias tóxicas y/o inflamables, incendios o explosiones que pueden producirse durante operaciones con sustancias peligrosas, capaces de provocar afectaciones graves a las personas, al medio ambiente y económicas. El Análisis de Riesgos de Procesos, es una disciplina que combina la evaluación ingenieril de procesos tecnológicos con técnicas matemáticas que permiten realizar estimaciones de frecuencias probabilísticas y consecuencias de posibles accidentes mayores, así como determinar las causas por las que podrían producirse. Un estudio para el análisis preliminar de riesgos de accidentes mayores fue ejecutado en la central termoeléctrica (CTE) “Otto Parellada” de La Habana, Cuba. Los resultados permitieron establecer que en la CTE están presentes los peligros de derrames tóxicos de ácido sulfúrico, derrames inflamables de fuel oíl, incendios y explosiones en el sistema de distribución de combustible y en la caldera. Las principales causas de riesgos de accidentes mayores identificadas fueron: fallo del sistema de control del flujo de agua a la caldera; fallo de los sistemas de protección; insuficiente inspección y mantenimiento e insuficiencias en el tratamiento químico del agua. Las medidas recomendadas para mejorar la gestión de seguridad de procesos de la CTE son de tipo técnico-organizativas, relacionadas con la frecuencia y alcance de las inspecciones, mantenimiento y actualización del manual del proceso, así como, proceder con la instalación de una planta para el tratamiento de los residuales que se generan en el proceso.

La corrosión atmosférica del acero al carbono fue estudiada en la refinería de petróleo de La Habana, Cuba. Cuatro sitios de exposición, tres bajo la condición exterior de exposición y uno a interior fueron colocados en la refinería durante un año de estudio. Categorías más elevadas de agresividad corrosiva para la condición exterior, C5 muy elevadas y CX extrema, fueron esperadas para atmósferas clasificadas como industrial-costera, industrial e industrial altamente contaminada debido a la deposición elevada de sales de iones sulfato. Se demostró, una equivalencia entre las dos variantes de estimación de la agresividad corrosiva de la atmósfera para las atmósferas clasificadas en la condición exterior de exposición. La elevada deposición de iones sulfato muy superior a la de iones cloruro trajo como resultado, diferencias entre la categoría de estimación y de determinación de la agresividad corrosiva para atmósferas clasificadas como industrial e industrial altamente contaminada. La categoría estimada fue elevada (C4) y la determinada media (C3). Sin embargo, para una atmósfera clasificada como industrial-costera, donde la deposición de iones cloruro resulta más elevada sin llegar a ser superior a la de iones sulfato, existió una equivalencia entre las dos variantes de estimación y la determinación elevada (C4) de la agresividad corrosiva para la condición exterior de exposición. La deposición de las sales de iones cloruro continúa siendo el factor más influyente en la corrosión atmosférica del acero al carbono, demostrándose en este estudio, para una atmósfera clasificada como industrial altamente contaminada.

resumo Estima-se que a pandemia do coronavírus (Sars-Covid-19) deverá repercutir de diversas maneiras e intensidades sobre a produção, a distribuição e a oferta de alimentos. Neste artigo discutimos o alcance e a profundidade da crise decorrente do Covid-19 sobre a agricultura e o agronegócio do Brasil e analisamos as repercussões potenciais e os efeitos da sobre a agricultura familiar, o setor de processamento de carnes e a distribuição de alimentos. A metodologia foi baseada na escolha de um conjunto de indicadores e variáveis sobre a agricultura e o agronegócio tomando como referência o contexto nacional e o cenário global. Buscamos informações da imprensa e revisamos uma ampla quantidade de materiais e dados de conjuntura publicados por diversos organismos nacionais e internacionais, assim como agentes privados. As conclusões da análise apontam que a pandemia poderá ter efeitos benéficos e aumentar a oferta da produção e a inserção internacional do agronegócio do Brasil. A demanda por alimentos está aumentando e é possível que o acirramento da disputa comercial Estados Unidos da América versus China amplie as exportações. A análise também indica problemas potenciais no abastecimento do mercado interno e eventuais aumentos de preços, assim como inflação de alimentos, que decorre tanto do aumento da demanda como dos custos de produção em razão da desvalorização cambial, que representa estímulo à exportação. Os efeitos da pandemia da Covid-19 sobre a agricultura familiar e o abastecimento dos mercados locais foi mais forte no início da pandemia quando houve restrições ao comércio e a circulação de produtos. As políticas públicas e o papel do Estado não se demonstram eficazes na crise, especialmente no que concerne aos problemas de contaminação nos frigoríficos e abatedouros. Encerramos sugerindo para a necessidade de reposicionar o sistema alimentar tornando-o mais resiliente e sustentável.

Abstract Background In medicine and dentistry, 3D technology allows the virtual planning and printing of surgical replicas of anatomical structures that can facilitate certain transplant procedures. In dentistry, 3D technology is useful in autogenous tooth transplantation. Case presentation We present a clinical case of an ectopic mandibular second premolar, describing the preoperative planning with dental replicas and the autotransplantation surgery. 3D prints of the surgical replica of the tooth to be transplanted was made using an Objet30 Prime® Printer, PolyJet. Clinical controls performed at 3, 6 and 12 months indicated the satisfactory evolution of the transplanted tooth. Conclusion 3D additive manufacturing technology allows the preparation of a new recipient socket with the aid of a surgical replica of the tooth to be transplanted, thus minimizing handling and extraoral time.

Este proyecto trata de un robot que riega los cultivos mientras se moviliza con energía solar, que será almacenada en baterías, para que cuando el clima no le favorezca tenga energía para continuar trabajando. Además, tendrá la capacidad de detectar si hay personas en las parcelas, hacer un alto o cambiar la ruta y así poder evitar accidentes. El sistema también es capaz de detectar la temperatura cuando inicia el proceso de riego. Se ha decidido implementar la energía solar, ya que las máquinas utilizan petróleo que al quemarse generan grandes cantidades de desechos dañinos para el medio ambiente. Esto trae como consecuencia el cambio climático. la energía solar no contamina y es gratis, es por esto que tenemos que aprovechar esta fuente de energía renovable para capturarla y almacenarla. Aquí se transforman los fotones en energía eléctrica que usamos para darle vida a nuestro entorno y así no causaremos daños irreparables a nuestro medio ambiente.

This paper describes a method for increasing the accuracy and precision of temperature measurements of a liquid based on the central limit theorem. A thermometer immersed in a liquid exhibits a response with determined accuracy and precision. This measurement is integrated with an instrumentation and control system that imposes the behavioral conditions of the central limit theorem (CLT). The oversampling method exhibited an increasing measurement resolution. Through periodic sampling of large groups, an increase in the accuracy and formula of the increase in precision is developed. A measurement group sequencing algorithm and experimental system were developed to obtain the results of this system. Hundreds of thousands of experimental results are obtained and seem to demonstrate the proposed idea’s validity.

The plant vasculature is a central organ for long-distance transport of nutrients and signaling molecules that coordinate vegetative and reproductive processes, and adaptation response mechanisms to biotic and abiotic stress. In angiosperms, the sieve elements are devoid of nuclei, thus depending on the companion cells for the synthesis of RNA and proteins, which constitute some of the systemic signals that coordinate these processes. Massive analysis approaches have identified proteins and RNAs that could function as long-range signals in the phloem translocation stream. The selective translocation of such molecules could occur as ribonucleoprotein complexes. A key molecule facilitating this movement in Cucurbitaceae is the phloem protein CmPP16, which can facilitate the movement of RNA and other proteins into the sieve tube. The CmPP16 ortholog in Citrus CsPP16 was characterized in silico to determine its potential capacity to associate with other mobile proteins and its enrichment in the vascular tissue. The systemic nature of CsPP16 was approached by evaluating its capacity to provide phloem-mobile properties to antimicrobial peptides (AMPs), important in the innate immune defense. The engineering of macromolecular trafficking in the vasculature demonstrated the capacity to mobilize translationally fused peptides into the phloem stream for long-distance transport. The translocation into the phloem of AMPs could mitigate the growth of Candidatus Liberibacter asiaticus, with important implications for crop defense; this system also opens the possibility of translocating other molecules to modulate traits, such as plant growth, defense, and plant productivity.

Este trabajo se enfoca en el cálculo y validación de los parámetros usados para la generación de caudales de máximas avenidas a lo largo de 16 puntos de interés en el cauce principal del río Biabo. Debido a la insuficiente información de mediciones meteorológicas e hidrométricas dentro de la cuenca, se utilizó la información grillada de precipitación diaria de la base de datos PISCO v2.1 del SENAMHI, el modelo de curvas de duración frecuencia del estudio ILLA-SENAMHI-UNI, y el hidrograma unitario de Snyder, y los resultados obtenidos fueron calibrados en base a los registros de caudales máximos de la estación hidrométrica Requena-Biabo. Así, por ejemplo, para la cuenca de la estación Requena-Biabo, la comparación entre los caudales de máximas avenidas generados con los caudales registrados para diferentes tiempos de retorno, el error obtenido fluctúa entre ±5%.

Abstract Introduction Prader-Willi Syndrome (PWS) is a genetic disorder caused by the lack of expression of certain paternal genes located on chromosome 15q11-q13. This anomaly causes cognitive, neurological and endocrine abnormalities, among which one of the most important is hyperphagia. The aim of this study was to assess the oral health of children with PWA and to establish preventive criteria. Results Thirty patients with PWS (mean age 10.2 years) and 30 age- and gender-matched controls were included in the study. Twenty-six patients with PWS(86.6%) followed dietary treatment prescribed by their endocrinologist. Individuals with PWS had a mean caries index of 53.3% and Decayed Missing Filled teeth (DMFT) index 2.5, and 53.3% had gingivitis, in the control group the respective figures were 43.3%, 0.93, and 60%. Only the DMFT index (p 0.017) presented significant differences. Regarding stimulated salivary secretion, patients with PWS presented a mean of 0.475 ml/min with a pH of 6.15, while controls presented a mean of 0.848 ml/min with a pH of 7.53; the differences between the groups were statistically significant in both cases (p 0.032 and p 0.0001 respectively). The population with PWS presented a higher plaque index (> 2) than their healthy peers, but the differences were not significant. Conclusion Pediatric patients with Prader-Willi syndrome have an increased risk of caries and gingivitis. The children with this syndrome have a decreased salivary flow and a more acidic salivary pH. In these patients, dental care is an essential part of their multidisciplinary medical treatment.

Abstract Background With the advent of endovascular techniques, alternate sites such as the pedal and radial arteries can now be accessed when treating peripheral arterial disease to reduce procedural complications, shorten recovery time, and improve patient comfort. However, a paucity of literature exists on the availability of support devices that can be utilized during challenging cases. Case presentation A 70 year-old female patient presented for evaluation of severe lifestyle-limiting left-sided claudication refractory to maximal medical therapy. Angiography revealed a chronic total occlusion of the left external iliac artery, which was treated successfully by percutaneous intervention via a primary transpedal approach and with the assistance of the Outback® Elite re-entry device. The patient was discharged 2 h after the procedure and reported significant symptom improvement at follow-up. Conclusion This case highlights a newly adopted endovascular approach through an alternate access site and illustrates how the Outback® Elite device can be used as an adjunctive tool in the treatment of complex lower-extremity vascular lesions.

Given a graph $G=(V,E)$ and a vertex $v \in V$, by $N(v)$ we represent the open neighbourhood of $v$. Let $f:V\rightarrow \{0,1,2\}$ be a function on $G$. The weight of $f$ is $\omega(f)=\sum_{v\in V}f(v)$ and let $V_i=\{v\in V \colon f(v)=i\}$, for $i=0,1,2$. The function $f$ is said to be \begin{itemize} \item a Roman $\{2\}$-dominating function, if for every vertex $v\in V_0$, $\sum_{u\in N(v)}f(u)\geq 2$. The Roman $\{2\}$-domination number, denoted by $\gamma_{\{R2\}}(G)$, is the minimum weight among all Roman $\{2\}$-dominating functions on $G$; \item a Roman dominating function, if for every vertex $v\in V_0$ there exists $u\in N(v)\cap V_2$. The Roman domination number, denoted by $\gamma_R(G)$, is the minimum weight among all Roman dominating functions on $G$. \end{itemize} It is known that for any graph $G$, $\gamma_{\{R2\}}(G)\leq \gamma_R(G)$. In this paper, we characterize the trees $T$ that satisfy the equality above.

Las estructuras de hormigón armado expuestas al ambiente agresivo costero de Cuba, han presentado plazos de vida útil muy inferiores a los 50 años. Los problemas de deterioro se deben fundamentalmente a la intensidad elevada del fenómeno de la corrosión atmosférica del acero de refuerzo embebido en el hormigón armado. Los costos en los trabajos de reparación en las estructuras continúan siendo económicamente muy significativos. Específicamente en zonas muy próximas al mar en las costas cubanas, los valores promedios anuales de deposición de las sales de iones cloruro transportadas en el aerosol marino ocupan el tercer lugar a nivel mundial. No obstante, debido a los niveles elevados de humedad relativa, Cuba ocupa un lugar supremo a nivel mundial en la obtención de niveles de agresividad corrosiva de la atmósfera entre muy elevado y extremo en los litorales costeros norte y sur. Todo esto justifica, la obtención de innovaciones basadas en los requerimientos tecnológicos en cuanto al incremento de la calidad del hormigón en Cuba, con el propósito de construir estructuras de hormigón armado altamente resistente al ambiente agresivo costero. Los resultados obtenidos están permitiendo en la actualidad a todas las empresas y entidades del país en la rama de la construcción, realizar las labores de diseño, construcción e inversión con los requerimientos tecnológicos que permiten incrementar la durabilidad de las estructuras de hormigón armado con plazos de vida útil superiores a 50 años a todo el patrimonio construido y que se construye, sin costos adicionales en trabajos de reparación.

Resumo: O artigo tem como objetivo analisar a imersão social da economia em distintos mercados agroalimentares brasileiros a partir de uma perspectiva institucionalista. Embasado em um conjunto de autores, referências bibliográficas e entrevistas, visa complementar o debate sobre mercados na sociologia rural e econômica que tem privilegiado nas suas análises as abordagens de rede e de campo. O argumento defendido é o de que os atores sociais, antes de estabelecerem redes de relações e transações econômicas ou posicionarem-se no interior do campo (mercado) econômico, já compartilham um conjunto de valores culturais comuns (instituições) que são os responsáveis por construir os mercados locais nos quais interagem. A partir de pesquisa empírica demonstra-se como o processo de imersão social da economia em três mercados alimentares brasileiros – A Feira Central de Campina Grande/PB, a Feira de Caruaru/PE e a Feira do Pequeno Produtor de Passo Fundo/RS – é construído e reproduzido por meio de quatro instituições sociais principais: a barganha, a variedade de produtos ofertados, o preço e a qualidade atribuída aos alimentos. Por sua vez, são essas instituições as responsáveis por orientar as práticas de comercialização e consumo dos atores nos mercados pesquisados.

The Coronavirus disease 2019 (COVID-19) pandemic halted human activities globally in multiple sectors including tourism. As a result, nations with heavy tourism, such as Belize, experienced improvements in water quality. Remote sensing technologies can detect impacts of “anthropauses” on coastal water quality. In this study, moderate resolution imaging spectroradiometer (MODIS) satellite data were employed along the Belizean coast to investigate impacts of the COVID-19 shutdown on water quality. The attenuation coefficient at 490 nm, Kd(490), was used as an indicator of water quality, with a lower Kd(490) indicating increased water clarity. Four Coastal Management Zones were characterized by marine traffic as high traffic areas (HTAs) and two as low traffic areas (LTAs). Monthly composites for two periods, 2002–2019 (baseline) and 2020 were examined for Kd(490). For months prior to the COVID-19 shutdown in Belize, there was generally no significant difference in Kd(490) (p > 0.05) between 2020 and baseline period in HTAs and LTAs. Through the shutdown, Kd was lower in 2020 at HTAs, but not for LTAs. At the LTAs, the Kd(490)s observed in 2020 were similar to previous years through October. In November, an unusually active hurricane season in 2020 was associated with decreased water clarity along the entire coast of Belize. This study provides proof of concept that satellite-based monitoring of water quality can complement in situ data and provide evidence of significant water quality improvements due to the COVID-19 shutdown, likely due to reduced marine traffic. However, these improvements were no longer observed following an active hurricane season.

Besides the failures that cause accidents, there are the ones responsible for preventing the car’s motion capacity. These failures cause inconveniences to the passengers and expose them to the dangers of the road. Although modern vehicles are equipped with a failure detection system, it does not provide an online approach to the drivers. Third-party devices and skilled labor are necessary to manage the data for failure characterization. One of the most common failures in engines is called misfire, and it happens when the spark is weak or inexistent, compromising the whole set. In this work, two algorithms are compared, based on Wavelet Multiresolution Analysis (WMA) and another using an approach performing signal analysis based on Chaos using the density of maxima (SAC-DM) to identify misfare in a combustion engine of a working automotive vehicle. Experimental tests were carried out in a car to validate the techniques for the engine without failure, with failure in one piston, and with two failed pistons. The results made it possible to obtain the failure diagnosis for 100% of the cases for both WMA and SAC-DM methods, but a shorter time window when using the last one.

Let G be a graph with vertex set V(G) and f:V(G)→{∅,{1},{2},{1,2}} be a function. We say that f is an outer-independent 2-rainbow dominating function on G if the following two conditions hold: (i)V∅={x∈V(G):f(x)=∅} is an independent set of G. (ii)∪u∈N(v)f(u)={1,2} for every vertex v∈V∅. The outer-independent 2-rainbow domination number of G, denoted by γr2oi(G), is the minimum weight ω(f)=∑x∈V(G)|f(x)| among all outer-independent 2-rainbow dominating functions f on G. In this note, we obtain new results on the previous domination parameter. Some of our results are tight bounds which improve the well-known bounds β(G)≤γr2oi(G)≤2β(G), where β(G) denotes the vertex cover number of G. Finally, we study the outer-independent 2-rainbow domination number of the join, lexicographic, and corona product graphs. In particular, we show that, for these three product graphs, the parameter achieves equality in the lower bound of the previous inequality chain.

Introducción. Diversas ramas de la economía demandan estudios sobre protección de materiales en las condiciones especiales de Cuba. Muchas labores se han realizado sin considerar la agresividad corrosiva ambiental. Objetivos: resolver los problemas de deterioro permite aumentar la vida útil de estructuras, con importante ahorro económico, beneficios sociales y mínima afectación medioambiental. Métodos. Se estudió el comportamiento, los requerimientos tecnológicos y los métodos de protección de los materiales más empleados en la industria de la construcción. Resultados. Se establecieron los espesores necesarios para el lacado del aluminio y las mejoras en su proceso de obtención, con importantes ahorros y reducción del impacto medioambiental, así como el mecanismo de deterioro, los factores influyentes y los procedimientos para rehabilitar edificaciones patrimoniales. Se determinó la agresividad corrosiva de la atmósfera en zonas estratégicas de Cuba y su influencia en el deterioro de los materiales. Los resultados de las investigaciones reportadas sobre estos temas fueron obtenidos en las instituciones participantes y permiten la ejecución de diversos procesos, con criterios de durabilidad y vida útil, optimizando recursos, conservación y renovación de infraestructuras. Se concluye con resultados de alto nivel científico, pertinencia y actualidad, en concordancia con el desarrollo científico-técnico dentro y fuera de Cuba.

New chiral 1-(arylamino)imidazo[2,1-a]isoindole-2,5-dione derivatives were obtained in good to excellent yields via the cyclocondensation of 2-formylbenzoic acid and various α-amino acid arylhydrazides using water as the solvent in the presence of sodium dodecyl sulfate as the surfactant and under simple and minimum manipulation, without purification. The reaction is totally diastereoselective and gives access to the nitrogenated tricyclic core with a relative trans stereochemistry.