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2.
Acta Ortop Mex ; 35(2): 226-235, 2021.
Article in Spanish | MEDLINE | ID: mdl-34731929

ABSTRACT

INTRODUCTION: Knee dislocation is a rare injury but considered serious clinically since it can be accompanied by vascular and neurological injuries that if they do not have a timely diagnosis and treatment can lead to the loss of the limb. Regarding vascular injury, the optimal diagnostic method for the identification of this type of lesion is of the utmost importance. OBJECTIVE: To present the literature review on the epidemiology, classification and diagnostic approach of knee dislocation with or without associated vascular injury. METHODS: Report of the literature found in databases and analyses based on clinical experience and synthesis of these documents. CONCLUSION: Vascular injury is not an uncommon finding in the context of knee dislocation, with a high risk of complications and even amputation if an early diagnosis is not made, the authors recommend angio-CT to confirm the suspected diagnosis and not delay treatment.


INTRODUCCIÓN: La luxación de rodilla es una lesión poco común, pero considerada grave clínicamente, ya que puede acompañarse de lesiones vasculares y neurológicas que si no tienen un diagnóstico y tratamiento oportuno pueden llegar a la pérdida de la extremidad. Respecto a la lesión vascular es de suma importancia el método diagnóstico óptimo para la identificación de este tipo de lesiones. OBJETIVO: Presentar la revisión bibliográfica sobre la epidemiología, clasificación y aproximación diagnóstica de la luxación de rodilla con o sin lesión vascular asociada. MÉTODOS: Reporte de la literatura encontrada en bases de datos y análisis basados en experiencia clínica y síntesis de estos documentos. CONCLUSIÓN: La lesión vascular no es un hallazgo infrecuente en el contexto de una luxación de rodilla, tiene un riesgo elevado de complicaciones e incluso de amputación si no se realiza un diagnóstico temprano, los autores recomiendan la angio-TAC para confirmar la sospecha diagnóstica y no retrasar el tratamiento.


Subject(s)
Knee Dislocation , Vascular System Injuries , Amputation, Surgical , Humans , Knee Dislocation/diagnostic imaging , Knee Dislocation/surgery , Vascular System Injuries/diagnostic imaging
3.
Mar Pollut Bull ; 172: 112911, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34482251

ABSTRACT

In this work data of salinity, temperature, suspended particulate matter (SPM), chlorophyll-a, and phytoplankton concentration in the Gibraltar Strait coast, in the confluence of the Mediterranean Sean and the Atlantic Ocean, were analyzed together with 210Po, 40K, 210Pb and 234Th activity concentration in different types of bivalve molluscs at the same time-period. The physicochemical parameters were evaluated using the Copernicus Marine Environment Monitoring Service (CMEMS) products based on satellite observations. A multivariate statistical analysis, including contrasted natural radioactivity contents, allowed the discrimination of bivalve molluscs from Atlantic and Mediterranean coasts. Additionally, a cluster analysis determined a highly significant negative correlation 210Po concentration in molluscs and phytoplankton concentration suggesting that phytoplankton concentration in the water column is a determinant factor to regulate 210Po concentration in those animals. These results introduce a useful tool to calculate the radiological doses in seafood from chlorophyll satellite image.


Subject(s)
Bivalvia , Phytoplankton , Animals , Atlantic Ocean , Chlorophyll A , Environmental Monitoring
4.
Radiat Prot Dosimetry ; 194(2-3): 178-185, 2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34218283

ABSTRACT

Novel building materials were manufactured and analyzed for 226Ra, 232Th and 40K using an HPGe gamma-ray spectrometer. The results show that the highest value of 40K was 4530 Bq per kg which was measured in a sample containing fly ashes from olive stones. The highest values of 226Ra and 232Th activities were 181 and 185 Bq per kg, which were measured in a sample with fly ashes from the co-combustion of coal and coke, respectively. On the other hand, the lowest values of 40K, 226Ra and 232Th activities were obtained for samples incorporating mussel shells. The radiological health hazard parameters, such as radium equivalent activity (Raeq), activity concentration index (I), absorbed and effective dose rates, associated with these radionuclides were evaluated. These values are within the EU recommended limits in building materials, except for samples of concrete containing fly ashes from olive stones, coal and coke. This study has contributed to the inclusion of industrial wastes that have not been collected previously in the Naturally Occurring Radioactive Material (NORM) databases on radioactivity of building materials.


Subject(s)
Radiation Exposure , Radiation Monitoring , Radioactivity , Radium , Construction Materials , Potassium Radioisotopes/analysis , Radiation Dosage , Radium/analysis , Spain , Thorium/analysis
5.
Article in English | MEDLINE | ID: mdl-32545903

ABSTRACT

The aim of the present work was to characterize the products obtained from the treatment of phosphogypsum residue by means of two recovery routes, and also to evaluate the concentrations of heavy metals and radionuclides in the materials obtained and their leachates. In this way, it is possible to determine how the most hazardous components of phosphogypsum behave during procedures until their stabilization through CO2 fixation. This study provides an initial estimate of the possibilities of reusing the resulting products from a health and safety risk standpoint and their potential polluting capacity. The phases resulting from the transformations were controlled, and the behaviour of standard mortars manufactured from the resulting paste lime was studied. In all cases, an additional control of the leachate products was performed.


Subject(s)
Calcium Sulfate , Phosphorus , Construction Materials , Metals, Heavy
6.
Appl Radiat Isot ; 155: 108920, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31622844

ABSTRACT

The probabilities of locating peaks with a high relative peak-area uncertainty were determined empirically with nine types of peak-location software used in laboratories engaged in gamma-ray spectrometry measurements. It was found that it is not possible to locate peaks with a probability of 0.95, when they have a relative peak-area uncertainty in excess of 50%. Locating peaks at these relatively high peak-area uncertainties with a probability greater than 0.95 is only possible in the library-driven mode, where the peak positions are supposed a-priori. The deficiencies of the library-driven mode and the possibilities to improve the probabilities of locating peaks are briefly discussed.

7.
Clin Transl Oncol ; 21(10): 1364-1373, 2019 Oct.
Article in English | MEDLINE | ID: mdl-30798512

ABSTRACT

PURPOSE: Patients with recurrent glioblastoma (rGBM) have a poor prognosis, with survival ranging from 25 to 40 weeks. Antiangiogenic agents are widely used, showing a variable response. In this study, we explored the efficacy of carmustine plus bevacizumab (BCNU/Bev) for treating rGBM. METHODS/PATIENTS: In this study, we assessed 59 adult patients with histologically confirmed rGBM who were treated with BCNU/Bev as second-line regimen. The response rate (RR), progression-free survival (PFS) and overall survival (OS) were evaluated according to their molecular expression profile, including CD133 mRNA expression, MGMT methylation (pMGMT), PDGFR amplification, YKL40 mRNA expression, IDH1/2 condition, p53 and EGFRvIII mutation status. RESULTS: Median follow-up was 18.6 months, overall RR to the combination was 56.3%, and median PFS was 9.0 months (95% CI 8.0-9.9). OS from time of diagnosis was 21.0 months (95% CI 13.2-28.7) and from starting BCNU/Bev it was 10.7 months (95% CI 9.5-11.8). IDH1/2 mutations were found in 30.5% of the patients, pMGMT in 55.9% and high CD133 mRNA expression in 57.6%. Factors which positively affected PFS included performance status (p = 0.015), IDH+ (p = 0.05), CD133 mRNA expression (p = 0.009) and pMGMT+ (p = 0.007). OS was positively affected by pMGMT+ (p = 0.05). Meanwhile, YKL40 negatively affected PFS (p = 0.01) and OS (p = 0.0001). Grade ≥ 3 toxicities included hypertension (22%) and fatigue (12%). CONCLUSIONS: BCNU/Bev is a safe and tolerable treatment for rGBM. Patients with MGMT+/IDH+ derive the greatest benefit from the treatment combination in the second-line setting. Nonetheless, high YKL40 expression discourages the use of antiangiogenic therapy.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Bevacizumab/therapeutic use , Brain Neoplasms/drug therapy , Carmustine/therapeutic use , Glioblastoma/drug therapy , Neoplasm Recurrence, Local/drug therapy , AC133 Antigen/genetics , AC133 Antigen/metabolism , Adult , Aged , Angiogenesis Inhibitors/adverse effects , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Bevacizumab/adverse effects , Brain Neoplasms/blood supply , Brain Neoplasms/genetics , Brain Neoplasms/mortality , Carmustine/adverse effects , Chitinase-3-Like Protein 1/genetics , Colombia , DNA Modification Methylases/metabolism , DNA Repair Enzymes/metabolism , Drug Administration Schedule , Female , Genes, erbB-1 , Genes, p53 , Glioblastoma/blood supply , Glioblastoma/genetics , Glioblastoma/mortality , Humans , Isocitrate Dehydrogenase/genetics , Male , Methylation , Middle Aged , Mutation , Neoplasm Recurrence, Local/blood supply , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/mortality , Progression-Free Survival , RNA, Messenger/metabolism , Receptors, Platelet-Derived Growth Factor/genetics , Survival Analysis , Tumor Suppressor Proteins/metabolism , Young Adult
8.
Epidemiol Infect ; 146(7): 875-878, 2018 05.
Article in English | MEDLINE | ID: mdl-29619916

ABSTRACT

The clinical and pathologic characterisation of two fatal cases of tick-borne rickettsiosis in rural (El Valle) and urban (City of Panama) Panama are described. Clinical and autopsy findings were non-specific, but the molecular analysis was used to identify Rickettsia rickettsii in both cases. No ticks were collected in El Valle, while in the urban case, R. rickettsii was detected in Rhipicephalus sanguineus s.l., representing the first molecular finding in this tick in Panama and Central America.


Subject(s)
Rhipicephalus sanguineus/microbiology , Rickettsia rickettsii/physiology , Rocky Mountain Spotted Fever/diagnosis , Adolescent , Animals , Child , Fatal Outcome , Humans , Male , Panama , Rocky Mountain Spotted Fever/microbiology
9.
J Environ Radioact ; 186: 152-160, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29061309

ABSTRACT

There are very few data available of 236U in marine sediment cores. In this study we present the results from the first oceanic depth profile of 236U in a sediment core sampled in the North Atlantic Ocean, at the PAP site (4500 m depth, Porcupine Abyssal Plain (PAP) site, 49°0' N, 16°30' W). Additionally, the sediment core was radiologically characterized through the measurement of anthropogenic 137Cs, 239Pu, 240Pu, 129I and 14C and natural 210Pb, 40K and 226Ra. The measured 236U concentrations decrease from about 90·106 at g-1 at the seafloor down to 0.5·106 at g-1 at 6 cm depth. They are several orders of magnitude lower than the reported values for soils from the Northern Hemisphere solely influenced by global fallout (i.e. from 2700·106 to 7500·106 at g-1). 236U/238U atom ratios measured are at least three orders of magnitude above the estimated level for the naturally occurring dissolved uranium. The obtained inventories are 1·1012 at m-2 for 236U, 80 Bq m-2 for 137Cs, 45 Bq m-2 for 239+240Pu and 2.6·1012 at m-2 for 129I. Atomic ratios for 236U/239Pu, 137Cs/236U and 129I/236U, obtained from the inventories are 0.036, 0.11 and 2.5 respectively. Concentration profiles show mobilization probably due to bioturbation from the abundant detritivore holothurian species living at the PAP site sea-floor. The range of 236U, 137Cs, 239+240Pu and 129I values, inventories and ratios of these anthropogenic radionuclides are more similar to the values due to fall-out than values from a contribution from the Nuclear Fuel Reprocessing Plants dispersed to the south-west of the North Atlantic Ocean. However, signs of an additional source are detected and might be associated to the nuclear wastes dumped on the Eastern North Atlantic Ocean.


Subject(s)
Geologic Sediments/chemistry , Radioactive Fallout/analysis , Uranium/analysis , Water Pollutants, Radioactive/analysis , Atlantic Ocean , Radiation Monitoring
10.
Food Chem ; 229: 159-164, 2017 Aug 15.
Article in English | MEDLINE | ID: mdl-28372159

ABSTRACT

The latest EU Council Regulation 2016/52/Euratom updates the emergency limits on radionuclides in foods including 210Po and 90Sr, two of the most important radionuclides for radiological dose from the ingestion pathway. A novel and straightforward method has been developed for sequential determination of 90Sr and 210Po in food samples using ultra low-level liquid scintillation counting and alpha-particle spectrometry. For 90Sr analysis, the method makes use of stable strontium as yield tracer, and 210Po is determined through self-deposition using 209Po as a yield tracer. The quantification limit for this method is 25.0 and 2.0Bqkg-1 for 90Sr and 210Po, respectively. The proposed radiochemical separation can be completed within 2days for a batch of 12 samples. The radiochemical procedure was validated by its application for the measurement of IAEA certified reference materials, and through participation in a national intercomparison exercise. Results are also presented in seafood from the Mediterranean coast.


Subject(s)
Food Quality , Spectrum Analysis/methods , Strontium Radioisotopes/chemistry , Radioisotopes
11.
Talanta ; 160: 28-35, 2016 Nov 01.
Article in English | MEDLINE | ID: mdl-27591584

ABSTRACT

Measurement of radionuclides in marine samples, specifically radioactive pairs disequilibrium, has gained interest lately due to their ability to trace cutting edge biogeochemical processes. In this context, we developed a fast, direct method for determining (210)Pb and (210)Po water through the use of ultra low-level liquid scintillation counting and alpha-particle spectrometry respectively and through Eichrom Sr resins for the Po-Pb separation. For (210)Pb analysis, the method uses stable lead as a yield tracer measured by a robust ICP-MS technique, and (210)Po is determined through self-deposition using the conventional (209)Po yield tracer. The improvements of the method over other techniques are: a) the analysis can be completed within 6 days, simplifying other methods, b) very low limits of detection have been achieved -0.12 and 0.005mBqL(-1) for (210)Pb and (210)Po, respectively - and c) most of the method could be carried out in on-board analysis. We applied the method to different aqueous samples and specifically to marine samples. We determined (210)Pb and (210)Po in the dissolved fraction of Mediterranean Sea water and an estuary at the South-West of Spain. We found that it can be successfully employed to marine samples but we recommend to i) use a minimum of 20L water to measure the (210)Pb in the dissolved phase by LSC and lower volumes to measure total concentrations; ii) wait for (210)Pb and (210)Bi in secular equilibrium and measure the total spectrum to minimise the limit of detection and improve accuracy.

12.
Rev. argent. radiol ; 80(1): 16-26, mar. 2016. ilus, graf, tab
Article in Spanish | LILACS | ID: biblio-843207

ABSTRACT

OBJETIVO: Describir los efectos de la restricción moderada del sueño en las regiones cerebrales involucradas en los procesos de inhibición cognitiva, función motora y fluidez fonológica, utilizando imágenes por resonancia magnética funcional (RMf). Materiales y métodos: Se estableció una condición de sueño habitual y otra de restricción moderada en 12 estudiantes diestros de pre y posgrado de Medicina, de entre 20 y 40 años. En ambos estados se utilizó la prueba psicológica de atención d2 e imágenes de RMf con paradigmas de función motora, fluencia fonológica y atención del tipo inhibición de la función ejecutiva Stroop. La restricción moderada de sueño fue de al menos el 63% con respecto al sueño habitual. Resultados: Se encontraron diferencias significativas en la activación cerebral con RMf para la función motora (p<0,05) entre el ciclo de sueño regular y el de restricción moderada. La actividad cerebral en RMf con los paradigmas de atención Stroop y fluidez fonológica no mostró diferencias significativas, así como tampoco la prueba psicológica de atención d2. Discusión: Se encontró interferencia en las activaciones cerebrales de representación motora con la restricción moderada de sueño, pero no se hallaron diferencias significativas en las activaciones de atención tipo Stroop, ni en la tarea de fluencia fonológica o las pruebas de atención d2. Esto podría deberse a una insuficiente restricción del sueño o a eficientes mecanismos de compensación en los sujetos de este estudio. Conclusión: Existen diferencias en las activaciones cerebrales de representación motora en la restricción moderada del sueño medidas con RMf


OBJECTIVE: To describe the effects of moderate sleep deprivation in brain regions involved in cognitive inhibition processes, motor function, and phonological fluency using functional Magnetic Resonance Imaging (fMRI). Materials and methods: A sample of 12 under-graduate and post-graduate medical students, between 20 and 40 years, were subjected to a follow-up of the number of hours of regular sleep in order compare to a moderate sleep deprivation after a nightshift. The d2 attention test and fMRI studies were used in both groups in order to evaluate motor function, verbal fluency and cognitive inhibition, or Stroop paradigms. The moderate sleep deprivation was at least 63% with respect to the regular sleep pattern during the previous week. Results: Significant differences in brain activity were found in fMRI to measure motor function (P<0.05) comparing regular sleep cycle and moderate sleep deprivation. The brain activity with fMRI Stroop paradigms and phonological fluency showed no significant differences between the two conditions, likewise with the psychological attention test d2. Discussion: The fMRI showed interference on motor representation activations in moderate sleep deprivation. No significant differences in fMRI were found in the processes of cognitive inhibition or Stroop paradigms, in phonological fluency, or in the psychological attention test d2. These could be attributed to inadequate sleep deprivation or efficient compensation mechanisms in the subjects of this study. Conclusión: There is a difference showed in fMRI on motor representation activations in moderate sleep deprivation


Subject(s)
Humans , Male , Female , Adult , Sleep Disorders, Circadian Rhythm , Sleep , Sleep Deprivation , Magnetic Resonance Imaging , Polysomnography
13.
FAVE, Secc. Cienc. vet. (En línea) ; 14(1/2): 1-5, Dec. 2015. ilus
Article in English | LILACS-Express | LILACS | ID: biblio-1090325

ABSTRACT

In this paper we report and discuss the finding of all the stages of Ornithodoros puertoricensis (Argasidae) parasitizing the exotic reptiles Varanus dumerilii, Python regius and P. bivittatus, and its presence in the reptile terrariums in Panama city.


En este trabajo se reporta y discute el hallazgo de todos los estadios Ornithodoros puertoricensis (Argasidae) parasitando los reptiles Varanus dumerilii, Python regius y P. bivittatus, y su presencia en los terrarios de reptiles en ciudad de Panamá.

14.
Odontol. pediatr. (Lima) ; 14(1): 6-18, ene.-jul.2015. tab
Article in Spanish | LILACS, LIPECS | ID: lil-790452

ABSTRACT

El tratamiento oncológico actúa no solo en los tejidos enfermos, sino también sobre las células sanas, durante este proceso suelen ocurrir efectos secundarios que pueden aparecer bajo la forma de complicaciones bucales y sistémicas. Son ejemplos mucositis, xerostomía, las infecciones, bacterianas víricas y fúngicas, Objetivo: Evaluar la frecuencia de complicaciones bucales en los niños con cáncer que asistieron a la Facultad de Odontología antes del tratamiento antineoplásico y seis meses después de haber recibido oncoterapia y entrenamiento, para el control de las mismas. Materiales y métodos: La muestra estuvo constituida por 100 niños con diagnóstico de cáncer que procedían de los diferentes hospitales y clínicas privadas de Caracas y sus alrededores. Se realice un cuestionario a los representantes que acompañaban al niño, en el momento de la primera visita para obtener la información inicial, se examinaron los niños, se realizó el tratamiento correspondiente, se entrenaron a los representantes, se controlaron mensualmente por seis meses y se analizaron las complicaciones bucales Resultados: Los representantes no tenían conocimiento inicial sobre las complicaciones bucales. El grupo de edad más afectado fue el comprendido en edades menores a 5 años (48%); el género masculino fue el más afectado (63%); la neoplasia más frecuente fue Linfoma No Hodking (24%); el10% de los niños presento alguna complicación bucal siendo las más frecuentes candidiasis y ulceras. Conclusiones: Enfatizamos la importancia de participación activa del odontopediatra con los representantes del paciente, así como con el oncólogo pediatra, especialmente antes del tratamiento antineoplásico educando sobre los efectos del tratamiento oncológico, ya que son potencialmente nocivos, provocando diversas complicaciones bucales...


Cancer treatment act not only in diseased tissues, but also on healthy cells, during this process often occur side effects that may appear in the form of later oral and systemic. Examples mucositis, xerostomia, infections, bacterial, fungal and viral. Objective: To evaluate the frequency of oral complications in children with cancer who attended the faculty of dentistry before the antineoplastic treatment six months after having received oncoterapia and training, for the control of the same. Materials and methods: The sample consisted of 100 children with diagnosis of cancer that they came from different hospitals and private clinics in Caracas and its surroundings. Was a questionnaire representatives accompanying the child, at the time of the first visit to the initial information, they discussed children, corresponding treatment was carried out, trained representatives, they controlled every month for six months, and oral complications were analyzed Results: Parents had no initial knowledge on oral complications. The age group most affected was understood in ages younger than 5 years (48%); the male gender was the most affected (63%); the most common malignancy was Lymphoma non Hodgkin (24%); 10% of children presented some mouth being the most common candidiasis complication and ulcers. Conclusions: We emphasize the importance of active participation of the dentist with the representatives of the patient, as well as with the oncologist, pediatrician, especially before treatment antineoplastic educating about the effects of cancer treatment, since they are potentially harmful, causing various oral...


Subject(s)
Humans , Mouth Diseases/prevention & control , Oral Hygiene , Child , Radiation Oncology , Epidemiology, Descriptive , Observational Study , Prospective Studies , Cross-Sectional Studies
15.
Acta odontol. venez ; 52(1)2014. graf
Article in Spanish | LILACS | ID: lil-777817

ABSTRACT

La pérdida parcial o total de la dentición natural es el resultado más frecuente de caries dental o enfermedad periodontal. Estos, ocasionan la extracción temprana de las piezas dentarias permanentes trayendo como consecuencia la necesidad de rehabilitación al individuo afectado. Determinar las necesidades protésicas de los pacientes de la población de Río Chico-Edo. Miranda. Estudio descriptivo y transversal. El instrumento de recolección de datos fue la Historia Clínica empleada por ambos centros, se estudiaron 701 pacientes entre masculinos y femeninos que acudieron a solicitar tratamiento odontológico al ambulatorio urbano tipo III Centro de Especiales Médico Odontológicas (C.E.M.O.) y el ambulatorio urbano tipo II Asociación Damas Salesianas (ADS) durante el período agosto-noviembre 2010. Se elaboró una matriz de datos en el programa Excel para la organización de los datos. 72% de la muestra eran mujeres y 28% eran hombres. La edad más afectada fue entre 21 y 30 años (28%). De acuerdo a las necesidades protésicas el 71% requiere una o más prótesis fija, 26% requerían prótesis parciales removibles tanto dento-soportadas como dento-muco-soportadas y 3% requería de prótesis totales. Se ratifica la importancia de este estudio para proveer información a las entidades del Estado encargados de brindar los recursos para rehabilitar a nivel bucal a esta población.


The partial or complete loss of the natural dentition is the most frequent result of dental caries or periodontal disease. There from the early extraction of teeth permanent bringing as a result the need for rehabilitation tothose affected individual. To determine the population of Río Chico- Miranda State, Venezuela, patients prosthetic needs. descriptive and transversal study. The data collection instrument was the clinical history, used by bothenters, 701 patients of both sexes who came to seek dental treatment to urban ambulatory type III special medical dental (C.E.M.O.) Centre and urban ambulatory type II partnership Damas Salesianas (ADS) during the period August-November 2010. Developed an array of data inthe Excel program for the Organization of the data 72% 28% to the masculine and feminine gender. The most affected age was between 21 and 30 years (28%). Needs prosthetic : 71% requires one or more fixed prosthesis, 26% require removable dento-supported both dento-muco-supported partial dentures and dentures requires 3%. Confirms the importance of this study to provide information to State entities responsible for providing resources to rehabilitate oral level to this population.


Subject(s)
Humans , Male , Adult , Female , Dental Caries/etiology , Dental Prosthesis Design , Dental Restoration, Permanent , Dentition, Permanent , Periodontal Diseases/diagnosis , Periodontal Diseases/etiology , Dental Materials , Dentition , Oral Surgical Procedures, Preprosthetic , Prosthodontics , Tooth Extraction
16.
Popul Stud (Camb) ; 66(3): 297-310, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22788959

ABSTRACT

What is the optimum way of describing the age-specific fertility pattern by mathematical functions? We propose a parametric fitting model, based on a mixture of Weibull functions, which performs well for countries where the fertility curve shows a non-traditional pattern. We also consider a simplified version of this model with a reduced number of parameters that can be applied to fit fertility curves in countries where the fertility pattern exhibits a classical shape. To test the new model, fertility curves for a range of countries and years are fitted empirically. The results show that both versions of the new model outperform existing procedures in most cases.


Subject(s)
Birth Rate/trends , Models, Theoretical , Age Factors , Algorithms , Humans , Ireland , Spain , United Kingdom
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