Search Results (8)

A vertex u in a graph G totally dominates a vertex v if u is adjacent to v. A set S of vertices in a graph G is a total dominating set of G if every vertex of G is totally dominated by at least one vertex of S. For a total dominating set S of a graph G and a vertex v of G, let ${\sigma }_S\left(v\right)$ denote the number of vertices in S that totally dominate v. A total dominating set S in a graph G is a proper total dominating set if ${\sigma }_S\left(u\right)\ne {\sigma }_S\left(v\right)$ for every two adjacent vertices u and v of G. While proper total dominating sets in trees have been previously studied, the primary goal here is to extend this study to classes of trees with a symmetric structure or that possess subtrees with a symmetric structure. Those trees belonging to several of the most-studied classes of trees that possess a proper total dominating set are determined. Graphical structures of proper total dominating sets in these trees are investigated. The minimum cardinality of a proper total dominating set in a graph G is the proper total domination number of G. Characterizations are obtained for all trees T with a small proper total domination number. Other results and problems are also presented on proper total dominating sets in trees in general. Full article

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to the COVID-19 pandemic, has significantly impacted global public health. The proper diagnosis of SARS-CoV-2 infection is essential for the effective control and management of the disease. This study investigated the SARS-CoV-2 infection using RT-qPCR tests from laboratories in Bosnia and Herzegovina. We performed a retrospective study of demographic data and Ct values from 170,828 RT-qPCR tests from April 2020 to April 2023, representing 9.3% of total national testing. Samples were collected from 83,413 individuals across different age groups. Of all tests, 33.4% were positive for SARS-CoV-2, with Ct values and positivity rates varying across demographics and epidemic waves. The distribution was skewed towards older age groups, although lower positivity rates were observed in younger age groups. Ct values, indicative of viral load, ranged from 12.5 to 38. Lower Ct values correlated with higher positive case numbers, while higher Ct values signaled outbreak resolution. Additionally, Ct values decreased during epidemic waves but increased with the dominance of certain variants. Ct value-distribution has changed over time, particularly after the introduction of SARS-CoV-2 variants of interest/concern. Established Ct value trends might, therefore, be used as an early indicator and additional tool for informed decisions by public health authorities in SARS-CoV-2 and future prospective pandemics. Moreover, they should not be overlooked in future epidemiological events. Full article

Diving can have significant cardiovascular effects on the human body and increase the risk of developing cardiac health issues. This study aimed to investigate the autonomic nervous system (ANS) responses of healthy individuals during simulated dives in hyperbaric chambers and explore the effects of the humid environment on these responses. Electrocardiographic- and heart-rate-variability ($HRV$)-derived indices were analyzed, and their statistical ranges were compared at different depths during simulated immersions under dry and humid conditions. The results showed that humidity significantly affected the ANS responses of the subjects, leading to reduced parasympathetic activity and increased sympathetic dominance. The power of the high-frequency band of the $HRV$ after removing the influence of respiration, $\overline{P_{HF\perp }}$, and the number of pairs of successive normal-to-normal intervals that differ by more than 50 ms divided by the total number of normal-to-normal intervals, $\overline{pNN50}$, indices were found to be the most informative in distinguishing the ANS responses of subjects between the two datasets. Additionally, the statistical ranges of the $HRV$ indices were calculated, and the classification of subjects as “normal” or “abnormal” was determined based on these ranges. The results showed that the ranges were effective at identifying abnormal ANS responses, indicating the potential use of these ranges as a reference for monitoring the activity of divers and avoiding future immersions if many indices are out of the normal ranges. The bagging method was also used to include some variability in the datasets’ ranges, and the classification results showed that the ranges computed without proper bagging represent reality and its associated variability. Overall, this study provides valuable insights into the ANS responses of healthy individuals during simulated dives in hyperbaric chambers and the effects of humidity on these responses. Full article

The use of fishing aids called Fish Aggregating Devices (FADs) has become a polemic in the context of realizing sustainable fisheries management. On the one hand, the use of FADs can increase fishermen’s catches. However, on the other hand, the use of FADs without proper management will result in unsustainable fish availability due to overfishing. The FADs used are also not always correlated with increased catches. At certain times, FADs used by fishermen can be lost because they are carried away by the current, which is clearly very detrimental to both fishermen and the environment. Utilization of geospatial information is one of the efforts to connect existing policies regarding the use of FADs, safety aspects, and optimizing the number of fishermen’s catches. The main focus of this study is the utilization of geospatial information such as the modeling of ocean currents, analysis of potential fishing zones, analysis of sea depth positions, and analysis of prohibited zones for the placement of FADs. The model and policy analysis results are used to determine recommendations for the optimal placement of FADs in the northern sea of the province of Gorontalo. In this study, an analysis of the influence of FADs on the economy of the community, especially the coastal community of North Gorontalo Regency, was also carried out. Recommended areas for FAD placement are divided into class 1 (low recommendation), class 2 (medium recommendation), and class 3 (high recommendation). The results of the recommendation for FAD placement areas resulted in 5 FADs being in the level 1 area, 27 FADs being in the level 2 area, and 6 FADs being in the level 3 area. Installed FADs cannot be moved to a different location because the installation is permanent. The findings of this study will help those who install new FADs to decide on a secure site for their installation. By paying attention to the shape of FADs, fishing gear, and the conditions of placement of existing FADs, it can be analyzed that the main catch targets of fishermen are pelagic (pelagic) fish, which is evidenced by the catches of fishermen in North Gorontalo Regency, which are dominated by large pelagic fish and small pelagic fish with a total catch of 21,535,604 kg. in 2021. Thus, it can be inferred that FADs have a significant role in supporting the economy that revolves around fishers, especially in North Gorontalo Regency, and with the stock of pelagic fish, which is still relatively high, it is possible to support the economy of the people of North Gorontalo Regency in the long term. Full article

Worldwide, oral cancer is the sixth most common type of cancer. India is in 2nd position, with the highest number of oral cancer patients. To the population of oral cancer patients, India contributes to almost one-third of the total count. Among several types of oral cancer, the most common and dominant one is oral squamous cell carcinoma (OSCC). The major reason for oral cancer is tobacco consumption, excessive alcohol consumption, unhygienic mouth condition, betel quid eating, viral infection (namely human papillomavirus), etc. The early detection of oral cancer type OSCC, in its preliminary stage, gives more chances for better treatment and proper therapy. In this paper, author proposes a convolutional neural network model, for the automatic and early detection of OSCC, and for experimental purposes, histopathological oral cancer images are considered. The proposed model is compared and analyzed with state-of-the-art deep learning models like VGG16, VGG19, Alexnet, ResNet50, ResNet101, Mobile Net and Inception Net. The proposed model achieved a cross-validation accuracy of 97.82%, which indicates the suitability of the proposed approach for the automatic classification of oral cancer data. Full article

Forest and tree cover loss decreases the ecosystem services that they may provide such as food and livelihood, protection from calamities, oxygen to breathe, and storing of carbon. This study assessed the diversity, species composition, and carbon stock potential of trees located in Aurora, Philippines. Two areas were surveyed to represent preserved and developed ecosystems. The preserved ecosystem was represented by the ultramafic forest in Baler, Aurora, whereas the developed ecosystem was represented by the urbanizing portion of Dipaculao, Aurora. The sampling site in Baler included 27,400 m² plots and the site surveyed in Dipaculao had a total of 72.72 hectares of developed area. Results showed a higher tree diversity in Baler (H′ = 4.096) than in Dipaculao (H′ = 3.278). Species composition assessment also revealed a higher number of ecologically important species in Baler. Ecologically important species in Baler included 100% natives, 34.5% endemics, and 20.86% threatened. Dominant species in Baler were the native, endemic, and threatened Xanthostemon philippinensis Merr. and the native Teijsmanniodendron ahernianum (Merr.) Bakh. On the other hand, the developed ecosystem had 54.4% native, 4.41% endemic, and 11.76% threatened species. Dipaculao was dominated by introduced and invasive species such as Swietenia macrophylla King and Gmelina arborea Roxb. ex Sm. For the tree carbon stock assessment, a tremendous difference was found wherein the preserved ecosystem had 272.28 tons/ha carbon whereas the developed ecosystem had 16.28 tons/ha carbon. This study revealed ideal forest ecosystem characteristics in preserved forests with high diversity, the presence of many important species, and a large amount of carbon stock. This calls for immediate action from the government to continuously protect the natural forests and prioritize proper land use planning and the right choice of species to be integrated with developed areas to improve the ecosystem’s capacity to provide vital ecological services. Full article

Introduction: In recent years, an increase in healthcare-associated infections (HAIs) caused by resistant pathogens, which is a clinically troublesome trend, has been observed. The aim of the study was to analyze the microbial factors of HAIs and the drug resistance of microorganisms to selected antibiotics and their consumption. Material and Methods: The retrospective study included 3708 patients hospitalized in the intensive care unit (ICU) of the University Teaching Hospital in Wroclaw, who were diagnosed with 742 HAIs in the period from 1 January 2011 to 31 December 2018. The aim of the study was the analysis of microorganisms isolated in the respective clinical forms of HAIs, including the occurrence of “alert pathogens”, presence of multidrug-resistant (MDR) strains, and consumption of selected antibiotics. Findings: During the study period, 846 microorganisms were cultured in patients with HAIs, and among them, Acinetobacter baumannii MDR represented 31.8%; Klebsiella pneumoniae ESBLs, 11.3%; Pseudomonas aeruginosa MDR, 4.1% and MRSA, 2.2%; and Enterococcus spp. vancomycin-resistant enterococci (VRE), 1.3%. Among all the pathogens, Gram-negative bacteria (GNB) were dominant (71.6%). Gram-positive bacteria and fungi accounted for 21.6% and 7%, respectively. The total number of strains responsible for ventilator-associated pneumonia (VAP), urinary tract infection (UTI), and central line-associated blood stream infection (CLA-BSI) was as follows: 458 (54.1%), 274 (32.4%), and 114 (13.5%), respectively. Among the etiological factors of VAP, there was a prevalence of A. baumannii MDR (41.9%), as well as in the case of UTI (21.9%). With regards to CLA-BSI, MRCNS (29.8%) was the dominant pathogen. The “alert pathogens” accounted for 54.7% of all the analyzed strains. The MDR strains represented 72.6% and 9.7% among A. baumannii and P. aeruginosa, respectively. In the years 2011 vs. 2018, an increase in infections with MDR bacilli was observed, 34.6% vs. 61.0% (p = 0.0008), respectively, including A. baumannii MDR 16.54% vs. 34.56 % (p = 0.0009) and Enterobacterales ESBL+/AMPC 11.8% vs. 15.44 % (p = 0.3921). Resistance to methicillin was confirmed in 35.2% of S. aureus strains. Resistance to vancomycin was found among 30.9% of Enterococcus spp. The observed period was marked by an increase in the consumption of carbapenems: 197.7 vs. 235.9 defined daily dose (DDD)/1000 patients-days. Conclusions: Gram-negative bacteria were found to be dominant pathogens in healthcare-associated infections. The most frequently cultured pathogens were multidrug-resistant A. baumannii, K. pneumoniae ESBL(+), and P. aeruginosa. The study showed an increase in the incidence of “alert pathogens” and MDR bacilli, as well as the tendency of a growing resistance to antibiotics during the observed period. Microbiological analysis of HAIs and the consumption of antibiotics is the necessary element of the proper antibiotic policy in hospitals. Full article

The proper planning of storage structures, waterways, irrigation schemes, water harvesting, erosion control structures, and groundwater development strategies requires accurate estimation of surface runoff. However, hydrologists in Saudi Arabia face serious challenges, specifically due to the rare availability of surface runoff data. In this study, the soil conservation service-curve number (SCS-CN) method integrated with geographic information system (GIS) and remote sensing (RS) was utilized to estimate the surface runoff in Wadi-Uranah basin, in the western region of Saudi Arabia. Different thematic maps such as slope, hydrologic soil group (HSG), land use/land cover (LULC), and daily rainfall have been created in GIS environment and processed to generate the curve number (CN) and surface runoff maps. Based on the soil classification results, the study area was categorized into two HSGs (B and C). The dominant HSG was group C, representing about 98.8% of the total area. The LULC analysis showed four main land use types in the study region: urban, rocks, barren soil, and agricultural areas. Furthermore, the finding results showed that CN values for the normal conditions (CN_II) ranged between 74 and 93 in agricultural and both urban and rock areas, respectively. The CN_II values were further corrected using slope data to derive slope-adjusted CN_II. Moreover, the rainfall-runoff results showed an increase in the daily runoff of the study region with a minimum of 15 mm to a maximum of 74 mm. Another interesting result was rainfall-runoff linear regression analysis that showed a good correlation of 0.98. Additionally, the peak runoff hydrograph flows for 10-, 50-, and 100-year return periods obtained from the SCS-based dimensionless unit hydrograph were 828, 1353, and 1603 m³/s, respectively. Therefore, this study highlights that the SCS-CN method integrated with RS and GIS deserves further attention for estimating runoff of ungauged basins for better basins management and conservation purposes. Full article