45 research outputs found
Coulomb and nuclear excitations of narrow resonances in Ne-17
New experimental data for dissociation of relativistic 17Ne projectiles incident on targets of lead, carbon, and polyethylene targets at GSI are presented. Special attention is paid to the excitation and decay of narrow resonant states in 17Ne. Distributions of internal energy in the O15+p+p three-body system have been determined together with angular and partial-energy correlations between the decay products in different energy regions. The analysis was done using existing experimental data on 17Ne and its mirror nucleus 17N. The isobaric multiplet mass equation is used for assignment of observed resonances and their spins and parities. A combination of data from the heavy and light targets yielded cross sections and transition probabilities for the Coulomb excitations of the narrow resonant states. The resulting transition probabilities provide information relevant for a better understanding of the 17Ne structure
Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength
Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R3B/LAND setup with incident beam energies in the range of 300-450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type OA(p,2p)NA-1 have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry
Feeding behaviour and digestion physiology in larval fish – current knowledge and gaps and bottlenecks in research
Food uptake follows rules defined by feeding behaviour that determines the kind and quantity of food ingested by fish larvae as well as how live prey and food particles are detected, captured and ingested. Feeding success depends on the progressive development of anatomical characteristics and physiological functions and on the availability of suitable food items throughout larval development. The fish larval stages present eco-morpho-physiological features very different from adults and differ from one species to another. The organoleptic properties, dimensions, detectability, movements characteristics and buoyancy of food items are all crucial features that should be considered, but is often ignored, in feeding regimes. Ontogenetic changes in digestive function lead to limitations in the ability to process certain feedstuffs. There is still a lack of knowledge about the digestion and absorption of various nutrients and about the ontogeny of basic physiological mechanisms in fish larvae, including how they are affected by genetic, dietary and environmental factors. The neural and hormonal regulation of the digestive process and of appetite is critical for optimizing digestion. These processes are still poorly described in fish larvae and attempts to develop optimal feeding regimes are often still on a ‘trial and error’ basis. A holistic understanding of feeding ecology and digestive functions is important for designing diets for fish larvae and the adaptation of rearing conditions to meet requirements for the best presentation of prey and microdiets, and their optimal ingestion, digestion and absorption. More research that targets gaps in our knowledge should advance larval rearing
Fluoride Concentration in Saliva and Dental Caries Relation in Children from Fluorosis Endemic Area.
It was proved the association between fluoride
ingestion and dental low prevalence of dental
caries experience. Objetive: To study the association between the
caries experience, severity of fluorosis and sa-
liva concentration of fluoride in rural area. Material and methods: A descriptive, Trans-
versal and quantitative study was performed.
It was registered the dmft/DMFT, caries ex-
perience, fluorosis index, plaque index and
fluoride concentration determination using
potentiometric ion specific method in saliva,
drinking water and from the water supply were
performed. Data was analyze by Kruskal Wal-
lis and varianza analysis.Se ha demostrado asociación entre la ingesta
de fluoruro y disminución en la experiencia
de caries.Objetivo: Establecer la relación de la expe-
riencia de caries, la severidad de fluorosis y
la concentración de fluoruro en saliva, en una
población infantil rural. Materiales y métodos. Estudio descriptivo,
transversal y cuantitativo. Se registró el ceo y
CPOD, la experiencia de caries, índice de fluo-
rosis, prevalencia y severidad, concentración
de fluoruros en saliva y agua de consumo por
métodos incrementales en potenciometría de
Ión específico. Se realizó análisis de varianza
y la prueba de Kruskal Wallis
Streptococcus mutans en saliva y su relación con caries dental. En una población infantil de la comunidad de Tacoaleche Guadalupe, Zacatecas
La caries dental es frecuente en
humanos, la valoración del Strep-
tococcus mutans es importante
para el desarrollo de la caries.
La actividad de caries está re-
lacionada con la prevalencia de
Streptococcus mutans en saliva.
El objetivo del estudio fue relacionar Strep-
tococcus mutans en saliva y caries en niños
de Tacoaleche, Zacatecas. Se estudiaron 139
niños de 6-13 años de edad. Se determinó el
ceo/CPOD, IHOS y UFC/ml de Streptococcus
mutans, el coeficiente de variación Ð= 93%, se
determinó riesgo a caries con concentración
de ufc/ml de S. mutans y la experiencia relati-
va de caries. La prevalencia de caries fue del
67.6%, el promedio de ceo/CPOD fue de 2.4
y de IHOS 1.25, el 71.9% presentó riesgo bajo,
10.8% alto y 15.82% moderado, la experiencia
de caries relativa el 51.79% fue baja, 32.37%
resistente, 10.79% alto y 5.03% rampante.
Hubo correspondencia entre los niveles de
Streptococcus mutans y el CPOD. (150)La caries dental es una de las enfermedades
infecciosas más frecuentes en humanos, la
valoración de la composición de la flora mi-
crobiana es importante para el desarrollo de
la caries dental y así como la disposición de
nutrientes, el Streptococcus mutans aprove-
cha la presencia de carbohidratos producien-
do ácido y la subsecuente desmineralización
del esmalte. Estas especies son consideradas
como los principales agentes causales de la
caries y su presencia es valorada como un
factor importante de riesgo junto con la ex-
periencia de caries y la dieta entre otros. Una
actividad de caries alta está relacionada con
un incremento en la prevalencia de Strepto-
coccus mutans en saliva. El objetivo de este
estudio fue determinar la presencia de Strep-
tococcus mutans en saliva y su relación con
caries dental en una población infantil de la
comunidad de Tacoaleche Guadalupe, Zaca-tecas. Se estudiaron 139 niños con edades de
6-13 años. Se determino el ceo/CPOD, IHOS
y UFC/ml de Streptococcus mutans. Se de-
terminó el coeficiente de variación Ð inter e
intragrupal con una Ð= 93%, se recolectaron
muestras de saliva y se realizaron diluciones
seriadas para posteriormente realizar cultivos
en agar mitis salivarius y determinar el riesgo
a caries de acuerdo con la concentración de
ufc/ml de S. mutans y la experiencia relativa
de caries, se encontró una prevalencia de ca-
ries dental del 67.6 %, se encontró un valor
medio de ceo/CPOD de 2.4 y de IHOS 1.25, el
71.9% bajo presenta un riesgo, 10.8% alto y
solo 15.82 % moderado, en contraste con la
experiencia de caries relativa el 51.79 % tie-
ne una experiencia baja, 32.37% resistente,
10.79% alto y 5.03% rampante.Se detectó una
correspondencia entre los niveles de Strepto-
coccus mutans y el CPOD
Niveles de Streptococcus mutans y prevalencia de caries dental en una población de escolares de la zona urbana de la ciudad de Zacatecas
The oral health level and the role of Streptococcus mutans and dental plaque accumulation in
the development of dental caries are important factors for the analysis and determination of
importance as a risk factors, it have been demonstrated in preschool and scholars children,
deficient hygiene practices, and for these reasons is important to use microbiological proce-
dures in order to evaluate quantitative and qualitative the dental plaque conditions. The aim of
this work is to determine the prevalence of dental caries in a group of school children from 10-
13 years old from the urban area in Zacatecas City and determinate the presence of S.
mutans in saliva in order to establish a relation between DMFT and the amount of S. mutans.
It was determined the DMFT and the SOHI as well as the ufcs/mL of S. mutans in 150
children of both sex in a school of urban area in Zacatecas City, we found a 56% prevalence
of dental caries and a correspondence between the S. mutans levels and the DMFT index; for
this reason is important to control the amount of S. mutans in dental plaque.El estado de salud bucal, el papel que juega el Streptococcus mutans y la acumulación de
placa dental en el desarrollo de caries son factores importantes de análisis, para determinar
la importancia que tienen como factores de riesgo. Se ha demostrado que los niños en
edades de preescolar y de educación primaria no tienen buenos hábitos de higiene, de igual
forma es importante la utilización de procedimientos microbiológicos que permitan evaluar
en forma cuantitativa y cualitativa las condiciones de la placa dental. El objetivo de este
estudio es determinar la prevalencia de caries dental en un grupo de estudiantes de educa-
ción primaria de 10-13 años de la zona urbana de la ciudad de Zacatecas y determinar la
presencia y cantidad de S. mutans en saliva para establecer una correspondencia con el
CPOD. Se determinó el IHOS, CPOD y el ufc/mL de S. mutans a 150 niños de ambos sexos
de una escuela primaria de la zona urbana de la ciudad de Zacatecas y se encontró una
prevalencia de caries dental del 56%, así mismo se detectó una correspondencia entre los
niveles de S. mutans y el CPOD por lo que es importante establecer mecanismos de control
en la proliferación de este microorganismo
PRESENCE OF NITRATES AND NITRITES IN WATER FOR HUMAN CONSUMPTION AND THEIR IMPACT ON PUBLIC HEALTH IN SUGARCANE-PRODUCING AREAS
Water pollution has emerged as a consequence of human settlements, as well as from specific rural, agricultural, forestry and industrial activities within a region. It has been found that increasing use of nitrogen fertilizers also increases water pollution. Nitrates and nitrites that are dissolved in groundwater used for human consumption cause adverse health effects, such as production of nitrosamines (cause of cancer) and decrease of oxygen carrying capacity of the blood, known as blue baby syndrome. The aim of this study was to determine the relationship between the concentration of dissolved nitrates and nitrites in drinking water, and the incidence of esophagus and stomach cancer in the population living close to agricultural areas. The maximum concentration of nitrates (NO3-) in water for human consumption was 7.5 mg L-1. A total of 45 cases of esophagus and stomach cancer were identified, distributed in six agricultural municipalities studied. A weak correlation (r = 0.46, p < 0.05) was found between the factor of rational use of nitrogen in sugarcane cultivation and the number of cancer cases recorded in the area of study