Generation Time Research Articles

Genomic signatures of past megafrugivore‐mediated dispersal in Malagasy palms

Abstract Seed dispersal affects gene flow and hence genetic differentiation of plant populations. During the Late Quaternary, most fruit‐eating and seed‐dispersing megafauna went extinct, but whether these animals have left signatures in the population genetics of their food plants, particularly those with large, ‘megafaunal’ fruits (i.e. >4 cm—megafruits), remains unclear. Here, we assessed the population history, genetic differentiation and recent migration among populations of four animal‐dispersed palm (Arecaceae) species with large (Borassus madagascariensis), medium‐sized (Hyphaene coriacea, Bismarckia nobilis) and small (Chrysalidocarpus madagascariensis) fruits on Madagascar. We integrated double‐digest restriction‐site‐associated DNA sequencing (ddRAD) of 167 individuals from 25 populations with (past) distribution ranges for extinct (e.g., giant lemurs and elephant birds) and extant seed‐dispersing animals, landscape and human impact data, and applied linear mixed‐effects models to explore the drivers of genetic variation in Malagasy palms. Palm populations that shared more megafrugivore species in the past had lower genetic differentiation than populations that shared fewer megafrugivore species. This suggests that megafrugivore‐mediated seed dispersal in the past may have led to frequent gene flow among populations. In comparison, extant frugivore diversity only decreased genetic differentiation in the small‐fruited palm. Furthermore, genetic differentiation of all palm species decreased with landscape connectivity (i.e. environmental suitability, forest cover and river density) and human impact (i.e. road density), while migration rates of the small‐fruit palm increased with road density. Synthesis. Our results suggest that the legacy of megafrugivores regularly achieving long dispersal distances is still reflected in the population genetics of palms that were formerly dispersed by such animals. Furthermore, low genetic differentiation was possibly maintained after the megafauna extinctions through alternative dispersal (e.g. human‐ or river‐mediated), long generation times and long lifespans of these megafruit palms. Our study illustrates how species interactions that happened >1000 years ago can leave imprints in their population genetics.

Treponema pallidum subsp. pallidum strains DAL-1 and Philadelphia 1 differ in generation times in vitro as well as during experimental rabbit infection.

In this work, we determined that Treponema pallidum subsp. pallidum (TPA) DAL-1 (belonging to Nichols-like group of TPA strains) grew 1.53 (± 0.08) times faster compared to TPA Philadelphia 1 (SS14-like group) during in vitro cultivations. In longitudinal individual propagation in rabbit testes (n = 12, each TPA strain), infection with DAL-1 manifested clinical symptoms (induration, swelling, and erythema of testes) sooner than Philadelphia 1 infection, which resulted in a significantly shorter period of the experimental passages for DAL-1 (median = 15.0 and 23.5 days, respectively; p < 0.01). To minimize the confounding conditions during rabbit experiments, the growth characteristics of DAL-1 and Philadelphia 1 strains were determined during TPA co-infection of rabbit testes (n = 20, including controls). During two weeks of intratesticular co-infection, DAL-1 overgrew Philadelphia 1 in all twelve testes, regardless of inoculation ratio and dose (median of relative excess DAL-1 multiplication = 84.85×). Moreover, higher DAL-1 to Philadelphia 1 inoculum ratios appeared to increase differences in growth rates, suggesting direct competition between strains for available nutrients during co-infection. These experiments indicate important physiological differences between the two TPA strains and suggest growth differences between Nichols-like and SS14-like strains that are potentially linked to their virulence and pathogenicity.

Age-Stage, Two-Sex Life Table of an Alarming Quarantine Pest Trogoderma granarium on Stored Products

Trogoderma granarium (Coleoptera: Dermestidae) is a polyphagous pest of stored products and an alarming threat to food security around the globe. The current study is designed to construct the life table of T. granarium on four stored products, i.e., wheat, barley, rice, and maize at controlled conditions (33±1°C, 65% RH, and a photoperiod of 14 : 10 (L:D) h). The incubation period of T. granarium was longer (5.13 d) on maize and shorter (4.30 d) on wheat. The developmental period of 1st, 2nd, 3rd, and 4th larval instars of T. granarium was longer on maize than the other three hosts were significant. Statistical difference between the longevity of females and males was recorded, while no statistically significant difference was found in the preoviposition period. The mean fecundity values observed on wheat, barley, rice, and maize were 31.33±1.62, 26.21±1.49, 28.00±1.35, and 25.58±1.13, respectively. The highest fertility was observed in wheat and the lowest in maize. The net reproductive rate (R0) of T. granarium ranged from 8.66±2.86, 13.16±2.65, 12.53±2.27, and 10.23±2.32 offsprings on wheat, barley, rice, and maize, respectively. The highest gross reproductive value (GRR) was for T. granarium reared on barley (18.31±4.10/d), and the lowest was for maize (15.35±2.95/d). To complete the development, T. granarium took 48.97±0.68 d on maize, significantly higher than on other treatments (p&lt;0.05). The mean generation time (T) of T. granarium was considerably affected by tested products. Based on the results of the present study, maize is a less favorable diet for the development and reproduction of T. granarium and may be considered for the management of this detrimental pest.

Near-natural streams: Spatial factors are key in shaping multiple facets of zooplankton α and β diversity

In near-natural basins, zooplankton are key hubs for maintaining aquatic food webs and organic matter cycles. However, the spatial patterns and drivers of zooplankton in streams are poorly understood. This study registered 165 species of zooplankton from 147 sampling sites (Protozoa, Rotifers, Cladocera and Copepods), integrating multiple dimensions (i.e., taxonomic, functional, and phylogenetic) and components (i.e., total, turnover, and nestedness) of α and β diversity. This study aims to reveal spatial patterns, mechanisms, correlations, and relative contribution of abiotic factors (i.e., local environment, geo-climatic, land use, and spatial factors) through spatial interpolation (ordinary kriging), mantel test, and variance partitioning analysis (VPA). The study found that α diversity is concentrated in the north, while β diversity is more in the west, which may be affected by typical habitat, hydrological dynamics and underlying mechanisms. Taxonomic and phylogenetic β diversity is dominated by turnover, and metacommunity heterogeneity is the result of substitution of species and phylogeny along environmental spatial gradients. Taxonomic and phylogenetic β diversity were strongly correlated (r from 0.91 to 0.95), mainly explained by historical/spatial isolation processes, community composition, generation time, and reproductive characteristics, and this correlation provides surrogate information for freshwater conservation priorities. In addition, spatial factors affect functional and phylogenetic α diversity (26%, 28%), and environmental filtering and spatial processes combine to drive taxonomic α diversity (10%) and phylogenetic β diversity (11%). Studies suggest that spatial factors are key to controlling the community structure of zooplankton assemblages in near-natural streams, and that the relative role of local environments may depend on the dispersal capacity of species. In terms of diversity conservation, sites with high variation in uniqueness should be protected (i) with a focus on the western part of the thousand islands lake catchment and (ii) increasing effective dispersal between communities to facilitate genetic and food chain transmission.

Integrating generative AI into financial market prediction for improved decision making

This study provides an in-depth analysis of the model architecture and key technologies of generative artificial intelligence, combined with specific application cases, and uses conditional generative adversarial networks ( cGAN ) and time series analysis methods to simulate and predict dynamic changes in financial markets. The research results show that the cGAN model can effectively capture the complexity of financial market data, and the deviation between the prediction results and the actual market performance is minimal, showing a high degree of accuracy. Through investment return analysis, the application value of model predictions in actual investment strategies is confirmed, providing investors with new ways to improve the decision-making process. In addition, the evaluation of model stability and reliability also shows that although there are still challenges in responding to market emergencies, overall, GAI technology has shown great potential and application value in the field of financial market prediction. The conclusion points out that integrating generative artificial intelligence into financial market forecasts can not only improve the accuracy of forecasts, but also provide powerful data support for financial decisions, helping investors make more informed decisions in a complex and ever-changing market environment. choose.

Evaluating geometric measurement accuracy based on 3D model reconstruction of nursery tomato plants by Agisoft photoscan software

Measuring the vegetation structure of a plant with the help of 3D images is a non-destructive method that can be used to monitor the plant’s status during the growing season. Structure from motion (SfM) is a popular optical distance measurement method that uses 2D images to create 3D models. Identifying factors that influence the precision of SfM is important due to its increasing use in phenotyping. The primary objectives of this study were, i) to scrutinize the impact of imaging parameters—including, color checkerboard location, overlap size of images, and background filtering—on the quality indices of 3D models, and ii) to attain precise measurements of leaf area, stem diameter, and height through the combination of images captured from different camera shooting angles. The three nursery tomato plants were photographed at every five-degree rotation of the turntable, five different locations of color checkerboards, and five camera shooting angles. Results indicated the color checkerboard’s presence and position affect the quality indices of the 3D models. Visually and by the lowest mean keypoint size value, the least noisy 3D model was obtained when the wall of the plant pot was covered with a checkerboard. When the base-to-distance (b/y) ratio as the image overlap index increased from 0.1 to 0.2, the generation time of the 3D models decreased by more than two times. Optimal Mean Absolute Percentage Error (MAPE) values of 1.08 %, 1.01 %, and 1.38 % were achieved for the estimation of leaf area, stem diameter, and height, respectively. This was recorded by using images taken at 0°, 30°, and 105° vertical azimuth angles. Constructing a 3D model by integrating images captured from other angles or more azimuth angles represents numerous visual challenges and leads to problems of point mismatch, which affects the accuracy of measurements.

Coulomb-induced emission time shifts in high-order harmonic generation from H2+

Accurate emission times of high-order harmonic generation (HHG) are vital for high-precision ultrafast detection in attosecond science, but a quantitative analysis of Coulomb effects on this time is absent in the molecular HHG. Here, we investigate the Coulomb-induced emission-time shift in HHG of H2+ with two different internuclear distances R, where the times obtained via the Gabor transform of numerical data from solving the time-dependent Schrödinger equation are used as simulation experiment results. Based on the molecular strong-field approximation, we develop a trajectory-resolved classical model that takes into account the molecular two-center structure. By selecting appropriate electron trajectories and including Coulomb interactions, the classical trajectory method can reproduce Gabor emission times well. This consistence reveals that Coulomb tails cause an emission-time shift of ∼35 as at the R = 2.0 a.u. case and of ∼40-60 as at the R = 2.6 a.u. case under the present laser parameters when compared to the Coulomb-free quantum-orbit model. Our results are of significance to probe the attosecond dynamics via two-center interference.

Effects of Prey Switching at Different Stages on Life Parameters of Neoseiulus bicaudus

The phenomenon of prey switching is prevalent in the natural world and represents a strategic adaptation of predators to their environment. Neoseiulus bicaudus, a native predatory mite found in Xinjiang, serves as a natural enemy to numerous small pests. The utilization of Tyrophagus putrescentiae as an alternative prey for the mass breeding of N. bicaudus is employed to fulfill the demands of enhanced breeding efficiency and cost-effectiveness. Following the introduction of mass breed N. bicaudus into the agricultural ecosystem, there was a switching in the prey of N. bicaudus from Ty. putrescentiae to Tetranychus turkestani. The objective of this study was to investigate the impact of prey switching at various stages on N. bicaudus. This study employed the age-stage, two-sex life table to assess the life parameters of N. bicaudus undergoing prey switching at different stages. The results showed that the survival rate of N. bicaudus was significantly decreased, the developmental period was significantly prolonged, the fecundity was improved during prey switching, and the intrinsic rate of increase of N. bicaudus was significantly decreased. The negative effects of prey switching in larva and deutonymph stages were greater than those in protonymph and adult stages. The stage and age of N. bicaudus undergoing prey switching were positively correlated with the male ratio, and negatively correlated with the total preoviposition period and the mean generation time. The comprehension of prey switching effects on N. bicaudus can enhance our understanding of the predator adaptation to environmental changes and contribute to the artificial rearing and application of natural enemy.

Predicting the Output Performance of Triboelectric Nanogenerators Using Highly Representative Data‐Based Neural Networks

Triboelectric nanogenerators (TENGs) are promising potential sustainable power sources for wireless sensing networks within the Internet of Things (IoT) realm. Developing an efficient TENG evaluation model, characterized by high speed, accuracy, and representativeness, facilitates its integration into practical applications, which is urgent and lack of investigation currently. Herein, an artificial intelligence (AI) based evaluation model is developed to predict the performance of freestanding rotational TENGs (FR‐TENGs) for demonstration. An accurate and representative train dataset is essential for development of AI‐based evaluation model, which has been generated using finite element analysis and equivalent circuit simulation alongside the non‐dominated sorting genetic algorithm II. Through comprehensive experiments and simulations, the accuracy of the model has been verified in predicting the power output performance of FR‐TENGs, which has 99.6% (three design parameters) and 99.2% (seven design parameters) maximum train set accuracy. More importantly, the predicted results from the AI‐based evaluation model have notably expanded the coverage of data and significantly expedited the generation time from days to seconds. Herein, the use of AI in assessing the performance of TENGs is enhanced. The TENG design process can be significantly simplified, while maintaining a high evaluation model accuracy, thus promising advancements of IoT applications in future.

Performance and preference of larval parasitoid, Microplitis pallidipes (Hymenoptera: Braconidae), on 2 Spodoptera pest species.

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) and Spodoptera litura (Fabricius) are the main pests on corn (Poaceae: Gramineae). The performance of the larval wasp, Microplitis pallidipes Szépligeti (Hymenoptera: Braconidae), was reported on S. frugiperda and S. litura. In this study, we evaluated host selectivity, constructed an age-stage, 2-sex life table, and assessed the pest control potential of M. pallidipes against these 2 pests under laboratory conditions. In a 2-choice host preference experiment, M. pallidipes exhibited a stronger preference for S. frugiperda over S. litura and a distinct preference for second instars. We also investigated the parasitism of females that were either unfed or fed with 10% honey-water solution under different host densities and found that the highest parasitism rate was observed when M. pallidipes were fed with honey-water solution on the first day after mating and a presented female wasp:host ratio of 1:90. In a nonselective assay, M. pallidipes successfully completed a full generation on both hosts. However, the parasitoids exhibited higher fitness and population growth potential when reared on S. frugiperda, with a net reproductive rate (R0) of 24.24, an intrinsic rate of increase (r) of 0.20 per day, a finite rate of increase (λ) of 1.23 per day, and a mean generation time (T) of 15.69 days. This study elucidates the performance of M. pallidipes on 2 Spodoptera host species and offers insights into its biological control potential on lepidopteran pests.

Rationally designed chromosome fusion does not prevent rapid growth of Vibrio natriegens

DNA replication is essential for the proliferation of all cells. Bacterial chromosomes are replicated bidirectionally from a single origin of replication, with replication proceeding at about 1000 bp per second. For the model organism, Escherichia coli, this translates into a replication time of about 40 min for its 4.6 Mb chromosome. Nevertheless, E. coli can propagate by overlapping replication cycles with a maximum short doubling time of 20 min. The fastest growing bacterium known, Vibrio natriegens, is able to replicate with a generation time of less than 10 min. It has a bipartite genome with chromosome sizes of 3.2 and 1.9 Mb. Is simultaneous replication from two origins a prerequisite for its rapid growth? We fused the two chromosomes of V. natriegens to create a strain carrying one chromosome with a single origin of replication. Compared to the parental, this strain showed no significant deviation in growth rate. This suggests that the split genome is not a prerequisite for rapid growth.

Internal Solitary Waves in the Central Andaman Sea Observed by Combining Mooring Data and Satellite Remote Sensing

The behavioral characteristics of internal solitary waves (ISWs) in the central Andaman Sea were revealed by analyzing multisource satellite remote sensing images combined with synchronous mooring data. The relationship between the generation time and tides of ISWs in the central Andaman Sea was analyzed and discussed. The ISWs in the central Andaman Sea exhibit a notable semidiurnal tidal cycle, primarily occurring during the spring tide. Additionally, it was observed that larger currents can generate ISWs with larger amplitudes. The propagation velocity of the ISWs initially increases and then decreases from the source, with no significant overall change in the deep areas. Based on the analysis of satellite remote sensing images that cover the source of ISWs in the central Andaman Sea, the generation time of ISWs was estimated. A comparison was made between the estimated generation time and the tidal flow predicted from the TPXO 9 global tidal model at the location of the ISW source. It was found that ISWs are generated when the westward tidal flow reaches its maximum. The ISWs in the central Andaman Sea are generated between the islands of Car Nicobar and Teresa Island. They propagate eastward into the Andaman Sea, grow in amplitude, split into multiple waves, dissipate, and vanish in the waters near the Danao Islands. The entire life cycle of these waves lasts for approximately 3∼4 days.

Boosting genome-wide association power and genomic prediction accuracy for date palm fruit traits with advanced statistics

The date palm is economically vital in the Middle East and North Africa, providing essential fibres, vitamins, and carbohydrates. Understanding the genetic architecture of its traits remains complex due to the tree's perennial nature and long generation times. This study aims to address these complexities by employing advanced genome-wide association (GWAS) and genomic prediction models using previously published data involving fruit acid content, sugar content, dimension, and colour traits. The multivariate GWAS model identified seven QTL, including five novel associations, that shed light on the genetic control of these traits. Furthermore, the research evaluates different genomic prediction models that considered genotype by environment and genotype by trait interactions. While colour- traits demonstrate strong predictive power, other traits display moderate accuracies across different models and scenarios aligned with the expectations when using small reference populations. When designing the cross-validation to predict new individuals, the accuracy of the best multi-trait model was significantly higher than all single-trait models for dimension traits, but not for the remaining traits, which showed similar performances. However, the cross-validation strategy that masked random phenotypic records (i.e., mimicking the unbalanced phenotypic records) showed significantly higher accuracy for all traits except acid contents. The findings underscore the importance of understanding genetic architecture for informed breeding strategies. The research emphasises the need for larger population sizes and multivariate models to enhance gene tagging power and predictive accuracy to advance date palm breeding programs. These findings support more targeted breeding in date palm, improving productivity and resilience to various environments.

Biology and demographic statistics of fall armyworm fed on corn leaves at the laboratory

Spodoptera frugiperda was a new invasive species in Indonesia in 2019, causing an outbreak in Indonesia’s corn-producing areas. Information on the life cycle and potency of population growth of S. frugiperda is required to strengthen local management. The biology and demographic statistics of S. frugiperda were studied in laboratory conditions. The larvae were collected from corn in Padang for mass rearing by feeding with corn leaves until adulthood. The eggs resulting from rearing were used as the cohort to observe biological and demographic statistics parameters. The development time of the egg was three days while larvae 1st, 2nd, 3rd, 4th, 5th, and 6th were 1-3, 2-4, 2-4, 2-4, 2-5, and 4-6 days respectively. Prapupae and pupae were 1-2 and 7-9 days, while male and female adults were 2-11 and 6-15 days, respectively. Preoviposition, oviposition, and post-oviposition were each 3-9, 1-4, and 1-2 days. The fecundity reaches 182,78 eggs per female adult. The net reproductive rate of 50.43 females/female/generation, a gross reproductive rate of 269 individuals per generation, an intrinsic rate of increase of 0.2 day−1 with mean generation time (T) 37.34 days, and a doubling time (DT) requiring 2.31 days.

Genetic predictors of population resilience: A case study of native Brook Trout in headwater streams

AbstractObjectivePopulations of eastern Brook Trout Salvelinus fontinalis face threats from several sources, such as habitat fragmentation, climate change, and competition with introduced salmonids. As a native species, understanding how these populations will respond to disturbances is paramount to their management and effective conservation. A population's ability to respond to disturbance, its resilience, is influenced by several factors. One such group of factors is population genetics.MethodsWe calculated population resilience metrics based on transient dynamics using population projection matrix models. Long‐term demographic data from 23 headwater stream Brook Trout populations were used to parameterize models. Genetic data were collected, and genetic indices were calculated. Partial redundancy analysis was then used to evaluate relationships between resilience metrics and genetic indices.ResultInbreeding coefficient, rarefied allelic richness, pairwise genetic differentiation (FST), and effective population size were all found to be important variables in predicting resilience.ConclusionOur results suggest that genetic isolation may increase the demographic resilience in Brook Trout through faster generation times and higher juvenile survival, but this likely comes at the cost of increased extinction risk and truncated size structures. Genetic indices can provide insight into gene flow between populations, thus the relationship between population connectivity and resilience. Given the importance of connectivity to population resilience, restoring and maintaining movement corridors could affect resilience in headwater Brook Trout populations.

Biology and life table parameters of Paralobesia viteana (Lepidoptera: Tortricidae), grown on different grape cultivars.

The grape berry moth, Paralobesia viteana (Clemens), is an important pest of cultivated grapes in eastern North America. Damage is caused directly by larval feeding of grape clusters and indirectly by increasing fruit susceptibility to fungal and bacterial pathogens. Despite the impact of grape berry moth on grapes being widely recognized, there is a lack of understanding of the influence that different grape cultivars may have on grape berry moth development, reproduction, and population dynamics. In this study, we constructed age-stage 2-sex life tables for grape berry moth fed on 5 grape cultivars: Concord, Niagara, Riesling, Chambourcin, and Vidal, to examine the effects of diet on insect population development, survival, reproduction, and demographic parameters such as net reproductive rate, intrinsic rate of increase, finite rate of increase, and mean generation time. Our findings reveal that grape cultivar significantly influenced the neonate wandering period, larval developmental time, adult and female longevity, pupal weight, adult preoviposition period, oviposition period, mean generation time, age-stage-specific life expectancy, and reproductive value of P. viteana. However, diet type did not affect grape berry moth total fecundity or other demographic parameters. The highest female reproductive value was observed at 30-40 days of age, indicating that control tactics implemented during this time frame would have the greatest impact on reducing population increase. This study provides critical information on the effects of different grape cultivars on grape berry moth development, reproduction, and demography. These insights could lead to the development of management strategies that improve pest control and reduce economic losses in vineyards.

Pervasive relaxed selection in termite genomes.

Genetic changes that enabled the evolution of eusociality have long captivated biologists. More recently, attention has focussed on the consequences of eusociality on genome evolution. Studies have reported higher molecular evolutionary rates in eusocial hymenopteran insects compared with their solitary relatives. To investigate the genomic consequences of eusociality in termites, we analysed nine genomes, including newly sequenced genomes from three non-eusocial cockroaches. Using a phylogenomic approach, we found that termite genomes have experienced lower rates of synonymous substitutions than those of cockroaches, possibly as a result of longer generation times. We identified higher rates of non-synonymous substitutions in termite genomes than in cockroach genomes, and identified pervasive relaxed selection in the former (24-31% of the genes analysed) compared with the latter (2-4%). We infer that this is due to reductions in effective population size, rather than gene-specific effects (e.g. indirect selection of caste-biased genes). We found no obvious signature of increased genetic load in termites, and postulate efficient purging of deleterious alleles at the colony level. Additionally, we identified genomic adaptations that may underpin caste differentiation, such as genes involved in post-translational modifications. Our results provide insights into the evolution of termites and the genomic consequences of eusociality more broadly.

Pilot-scale plasma activated water treatment for decontaminating romaine lettuce and steamed rice cakes

The study investigated the effects of pilot-scale plasma activated water (PAW) on the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and indigenous mesophilic aerobic bacteria on romaine lettuce and steamed rice cake (SRC). PAW treatment was conducted by stirring 25 g of romaine lettuce and 80 g of SRC for 20–40 min at 195 rpm in 1 L of PAW, prepared by treating sterile distilled water with surface dielectric barrier discharge for 40 or 60 min. The microbial inactivation rates of foodborne pathogens and indigenous mesophilic aerobic bacteria ranged from 1.3 to 2.5 log on romaine lettuce and SRC, along with PAW generation time (P < 0.05). Inactivation rates of PAW generation time or treatment time against romaine lettuce and SRC were significantly different to the inactivation of distilled water treatments, respectively (P < 0.05). The pH, electrical conductivity, and hydrogen ion concentration correlated with nitrite and nitrate concentrations of PAW prepared at various PAW generation time. In situ pilot-scale PAW treatment also extended the shelf life of the romaine lettuce. The study demonstrates the feasibility of the pilot-scale PAW treatment to improve microbiological safety and its suitability of applying PAW to manufacture romaine lettuce and SRC products.

Analysis of Chaotic Logistic Map used to Generate Secret Keys

Chaotic logistic map is a good model which can be used to generate various secret keys used in data cryptography. In this paper research a detailed analysis of CLM will be introduced. The behavior of CLM will be studied to show how to select the best values of the CLM parameters (growth rate, initial population and the length of the population). Various ranges of the population growth and the initial population will be tested. It will be shown how to use the generated populations to form various secret keys. The sensitivity of CLM will be studied, and it will be shown that any minor changes in the CLM parameters will lead to change the generated population. The population generation time will be tested using various in length generated population, and some recommendation will be provided when dealing with data with big size. It will be shown that using CLM will provide a good security level when using the CLM parameters as a private key.

ECONOMIC FEASIBILITY OF ON-GRID PHOTOVOLTAIC SYSTEMS IN A SINGLE-FAMILY HOUSE IN RIO DE JANEIRO CITY

Brazil is a tropical country with favorable conditions for the generation and utilization of solar energy. This energy source becomes even more attractive when considering the dry periods that impact hydroelectric power generation in the country, resulting in an increase in energy costs reflected monthly in consumers' bills through tariff flags. In order to enhance residential architectural designs and promote energy efficiency, a feasibility study of photovoltaic systems was conducted, considering key economic indicators and the current tariff flags. To accomplish this, research was conducted in collaboration with Mounting Companies for a case study located in the city of Rio de Janeiro, adopting technical assumptions commonly used for residential photovoltaic system sizing. For the graphical sizing of the case study, factors such as the environment and summer and winter solstices were taken into account, and a shadow study was conducted to assess the potential loss of power generation by the photovoltaic system throughout the year. The shadow study revealed that, during both solstices, the optimal time for power generation by photovoltaic systems is between 9 a.m. and 6 p.m. Essentially, the calculated values of NPV (Net Present Value) and IRR (Internal Rate of Return) indicate that the project is economically viable and particularly advantageous during the yellow and red tariff flags, situations in which energy costs tend to be higher for consumers.