F. T. Silveira, G. V. A. Flores, C. M. Pacheco
et al.
Non-ulcerated cutaneous leishmaniasis (NUCL) is an atypical clinical form of leishmaniasis first described, in 1988, by Ponce and collaborators, in Honduras, Central America, characterized by isolated or disseminated closed skin lesions appearing as papules, nodules, or infiltrated plaques, primarily in adolescents and young adults. Leishmania (L.) chagasi was then identified as the causal agent of both NUCL and American visceral leishmaniasis (AVL) in Honduras, though NUCL has been reported as more prevalent. However, due to the uncertain taxonomic classification of the NUCL-causing parasite, especially since L. (L.) chagasi has not been associated to this form of the disease in South America, this study conducted a comprehensive taxonomic review incorporating phenotypic (biological and clinical-immunopathological) and genotypic (genomic/molecular) analyses. Biologically, Honduran parasite-LPG does not have Gal (β1,4) Man (α1)-PO4 side chains common to all Leishmania LPGs. From a clinical-pathogenic perspective, NUCL is unique, it does not ulcerate like cutaneous leishmaniasis due to L. (L.) chagasi or L. (L.) infantum. Molecular findings showed that the Honduran parasite is more ancestral than all known viscerotropic Leishmania species, exhibited an unprecedented structural variation on chromosome 17 with the highest frequency of genomic SNPs, formed a distinct phylogenetic lineage, and displayed a homozygous SNP profile typical of a parental (non-hybrid) parasite. Building on these findings, a new species, Leishmania (Leishmania) poncei n. sp. (Kinetoplastea: Trypanosomatidae), is proposed in honor of Professor Carlos Ponce, who first described NUCL in Honduras. This study formally classifies L. (L.) poncei n. sp. as a novel Leishmania species responsible for both NUCL and AVL in Honduras, Central America.
A comprehensive multivariate analysis of beam parameters and external features of linac located at two distinct geographical sites is studied. The analysis helps to maintain consistent beam delivery despite seasonal fluctuations. Over 1000 daily measurements collected via the PTW Quickcheck webline are examined using advanced visualization techniques from Python's Seaborn library, such as kernel density estimate plots, pair plots, and relational plots. The environmental impact is observed with temperature control within the treatment bunker which significantly stabilizes beam characteristics, even under seasonal fluctuations. This analysis underscores the value of multivariate techniques in improving the predictive assessment of linac performance. It reveals how consistent beam delivery can be maintained across regions despite seasonal influences - especially when bunker climate control and regular monitoring protocols are in place.
Radon is a radioactive noble gas, recognized as a carcinogenic agent, being affected by degree of ventilation. The aim of this preliminary study was to determine the concentration of indoor radon gas in schools, to estimate the main factors affecting their radon concentration levels and to analyze the effective dose received by students in Duhok schools. Therefore, the concentrations of radon were measured in 28 classrooms, from 13 schools located in Duhok city, using both RAD7 and Corentium monitor, from January 15-30, 2021. In all schools indoor radon was measured in four different scenarios of closed, natural and mechanical ventilation then, radon reduction rate between each case was calculated. In addition to that, exposure to annual effective dose of radon, for each different degree of ventilation, was evaluated. Furthermore, effects of building floors were studied. Results showed that maximum radon concentration, 121 Bqm-3, was recorded in closed ventilation, while minimum, 15 Bqm-3, was recorded in mechanical ventilation. Radon reduction rate in a mechanical ventilation is relatively large 81%. Also, results demonstrate that indoor radon levels at first floor, in all schools under study, were considerably greater than those at second and third floor (p < 0.05). The annual effective dose of all studied schools at 4 different cases of ventilation were found less than the worldwide average radiation dose of 3-10 mSv. So, it is not required to take any action to minimize the level of radon in schools under study.
This study explores the impact of solar flare events on radioactive materials, focusing in particular on the thorium decay chain. Previous research has indicated that gamma emitters are affected by solar flares, resulting in count-rate dips. In this study, we present, for the first time, concurrent gamma and beta count-rate measurements from a thorium radioactive source, revealing multiple dips in the count rate. Based on a consideration of the temporal relationship between beta and gamma emissions, we propose that the response to solar events originates primarily from beta emissions. To investigate this phenomenon further, we employ plastic scintillator beta detectors, enabling the examination of various radioactive sources and the study of neutrino interactions and their impact on decay rates. This experimental approach offers an opportunity to expand our knowledge of particle interactions and provides insights into the interplay between solar flares, neutrino flux, and the behavior of radioactive materials.
Radon exhalation rate is the rate of radioactive radon gas that escapes from the soil into the atmosphere. In this study exhalation rate of radon was measured for 33 samples of soil, in four districts of Duhok province, using two different techniques: one using radon concentration and other using radium content, by both alpha and gamma spectroscopy. For the radon measurement, alpha-sensitive RAD7 detector was used. While in the second method, radon exhalation rate was expressed as a function of radium concentration, measured by well type NaI (Tl) detector and other soil parameters. Analysis, shows that the average of radon exhalation rate, by the first technique, varies from 14.6 ? 3.2 to 55.7 ? 1.6 Bqm-2h-1, while by the second technique, it varies from 13.3 ? 2.4 to 50.6 ? 4.1 Bqm-2h-1. Overall, the measured values, for both methods at all the sample points, present a good correlation and less than global mean average recommendation.
Born in the aftermath of core collapse supernovae, neutron stars contain matter under extraordinary conditions of density and temperature that are difficult to reproduce in the laboratory. In recent years, neutron star observations have begun to yield novel insights into the nature of strongly interacting matter in the high-density regime where current theoretical models are challenged. At the same time, chiral effective field theory has developed into a powerful framework to study nuclear matter properties with quantified uncertainties in the moderate-density regime for modeling neutron stars. In this article, we review recent developments in chiral effective field theory and focus on many-body perturbation theory as a computationally efficient tool for calculating the properties of hot and dense nuclear matter. We also demonstrate how effective field theory enables statistically meaningful comparisons between nuclear theory predictions, nuclear experiments, and observational constraints on the nuclear equation of state.
The KIDS framework for the nuclear equation of state (EoS) and energy density functional (EDF) offers the possibility to explore systematically the effect of EoS parameters on predictions for a variety of observables. The EoS parameters can be varied independently of each other and independently of assumptions regarding the in-medium nucleon effective mass. Here I present a pilot study of the neutron skin thickness (NST) in nuclei of current interest. The results indicate that variations of the symmetry energy slope parameter L by roughly 10 MeV and variations of the droplet-model counterpart of the curvature parameter $K_τ$ by roughly 20 MeV affect predictions by comparable amounts. However, structural details may also have sizable effects on predictions, notably in the cases of $^{68}$Ni and $^{208}$Pb. This work is part of a systematic investigation of the NST within the KIDS framework and of a broader effort to constrain the density dependence of the nuclear symmetry energy.
Results of analyzes of the growth and development of species Pterocarya pterocarpa (Michx.) Kunth ex Iljinsk. of the Pterocarya Kunth genus (Juglandaceae DC. ex Perleb) — relict plant of the Arctic flora of the III period in ex situ conditions have been shown in the paper. Degree of adaptation of wingnut in ex situ conditions, its growth characteristics were assessed both in young and old age. The biomorphological structure of P. pterocarpa seedlings, the size and number of hypocotyls and germ layer were determined in the course of the study. The formation and growth of simple complex true leaves and the life cycle of germ layer were determined as a result of observations of seedlings. The growth of seedlings of wingnut occurs intensively from the third decade of April to the second decade of June under ex situ conditions have been showed the study. The final productivity of seedlings under in situ conditions was higher than under cultivation conditions in ex situ as was found under studying the growth and development of plant. The vegetation of the species P. pterocarpa under the conditions of Absheron begins from the second decade of March to the second decade of November; the duration of the growing season is several days. P. pterocarpa grows and develops normally in cultural conditions of Absheron on based of the analysis of the research.
MOPAC and LAMMPS molecular dynamics codes and reaction kinetics code based on multi-ionic continuum-based model are used to analyze the impact of gamma radiation on concrete hydration. The experimental studies showed that while cured with the low gamma dose concrete shows a statistically significant increase in its strength compared to conventionally cured concrete. The potential reason is the interactions of gamma rays with water causing concrete faster hydration. The question then to ask is would the higher gamma dose enhance the concrete curing further producing its higher strength. This paper provides in-depth numerical analyses of the high-dose gamma radiation effect on concrete based on molecular dynamics and reaction kinetics models. Under these conditions, it is assumed that gamma radiation interacting with water within the concrete induces water radiolysis. These numerical simulations show that the reactivity is generally increased in the presence of electrophiles. However, the early hydration models of tricalcium silicate (alite) and dicalcium silicate (belite) with H+, OH-, and H3O+ show that the hydration process is slowed down leading to a lower concrete strength. Additionally, the reaction kinetics model used to estimate the effect of [OH-] on tricalcium silicate hydration shows that an increase or decrease of [OH-] during tricalcium silicate hydration can respectively slow down or enhance its rate of hydration. The dose necessary to produce the water radiolysis resulting in varying [OH-] during tricalcium silicate hydration is required to be extremely high and therefore, will damage the concrete structure itself. This leads to the conclusion that increasing the gamma dose to concrete above that used in the experimental studies in order to induce water radiolysis will not improve concrete strength, therefore water radiolysis is not the required condition for improving concrete strength when cured under gamma radiation.
This paper presents the results of an analysis of a universal cooling system for the core of re- search reactors built on the passive principle of natural convection. A 3-D model, technologi- cal and design diagrams of the reactor installation are provided, along with examples of nu- merical evaluation of transients during the operation of the cooling circuit in normal and emergency modes to substantiate the possibility of using such a cooling system in research re- actors of small and medium power. The principal feature of the described passive system is the absence of not only active elements, such as circulation pumps and shut-off and control valves from the cooling circuit, but also of passive elements with moving parts, such as a check valve. The cooling circuit includes only vessels, piping and a heat exchanger. The absence of elements with mechanical moving parts can significantly reduce the likelihood of equipment failures and improve the reliability of such a cooling system while also reducing its cost. The versatility of the proposed system allows it to be used for a wide range of research reactor plants with various capacities, which are nowadays being developed designed to carry out programs in various areas of research and applied usages related to nuclear technologies.