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1.
Nat Commun ; 13(1): 2908, 2022 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-35614033

RESUMEN

The economy of a country is exposed to disruptions caused by natural and man-made disasters. Here we present a set of probabilistic risk indicators, the Average Annual Loss (AAL) and the Loss Exceedance Curve (LEC), regarding to production, employment, Gross Domestic Product (GDP), Gross Regional Product (GRP), export volume, inflation, tariff revenue, among others, due to earthquakes. All indicators are computed using a systematic probabilistic approach, which integrates the seismic risk assessment with spatial computable general equilibrium models, both robust and well-known frameworks used worldwide in their respective fields. Our approach considers the induced damage and frequency of occurrence of a vast collection of events that collectively describe the entire seismic hazard of a country, giving us a better and more complete understanding of the full consequence of earthquakes. We illustrate this approach with an example developed for Chile.


Asunto(s)
Desastres , Terremotos , Producto Interno Bruto , Humanos , Medición de Riesgo , Factores de Riesgo
2.
Bull Environ Contam Toxicol ; 104(5): 568-574, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32322933

RESUMEN

Water quality degradation by organochlorine pesticides and potentially toxic elements is of worldwide concern. This research explores groundwater conditions, regarding organochlorine pesticides and potentially toxic elements, in Hopelchen, Campeche, which is located in the buffer zone of the Calakmul Biosphere Reserve. Unfortunately, agriculture is allowed and agrochemical use is not monitored and sanctioned. Results show that Heptachlor, Endosulfan, and Dieldrin, all recognized carcinogens, had concentrations above the Mexican normative recommended values. Conversely, Cd and Ni concentrations were below recommended values. These results demonstrate that government intervention involving immediate control over agrochemical use is mandatory. Also, the results underscore the contamination of groundwater in several of the Calakmul Biosphere Reserve's buffer zones by organochlorine pesticides concentrations, posing a probable threat for local inhabitants who consume this water and use it for recreation.


Asunto(s)
Monitoreo del Ambiente/métodos , Agua Subterránea/química , Sustancias Peligrosas/análisis , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Agricultura , Dieldrín/análisis , Endosulfano/análisis , Heptacloro/análisis , México , Recursos Hídricos/provisión & distribución
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 227: 117570, 2020 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-31669938

RESUMEN

Phenolic compounds (PC) have been proposed as natural antioxidant agents that protect cells against oxidative stress-related diseases. Nonetheless, their low bioavailability forecasts controversy about mechanisms on their in vivo scavenging activity against reactive oxygen species (ROS). It has been proposed that PC reduce directly ROS concentration. An alternative or complementary action of PC could be the activation of the cell's antioxidant pathway, involving the regulation of gene expression, like that initiated by the Nrf2 transcription factor. To date there is not enough experimental data to support or discard this possibility. In the present study, we evaluated the use of several PC to prevent peroxidation of macromolecules and to elicit the activation of the Nrf2 transcription factor in H2O2-stresed IEC-6 enterocytic cell line. Synchrotron microspectroscopy demonstrated that PC compounds protected proteins, lipids and nucleic acids against oxidation induced by H2O2. Immunofluorescence results showed that treatment with quercetin (Qc), catechin (Cat) and capsaicin (Cap) induced the translocation of Nrf2 into the nucleus, at the same level as did H2O2 treatment, thus mimicking the action of the endogenous cell response to peroxidation. Even though the detailed mechanism still needs to be elucidated, we demonstrated the activation of Nrf2 by PCs in response to oxidative stress.


Asunto(s)
Antioxidantes/farmacología , Capsaicina/farmacología , Catequina/farmacología , Estrés Oxidativo/efectos de los fármacos , Quercetina/farmacología , Animales , Línea Celular , Peróxido de Hidrógeno/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Ratas , Espectroscopía Infrarroja por Transformada de Fourier
4.
Acta Ortop Mex ; 31(4): 182-188, 2017.
Artículo en Español | MEDLINE | ID: mdl-29216694

RESUMEN

BACKGROUND: Adduct congenital talipes equinovarus (CTE) or clubfoot is a common musculoskeletal malformation affecting between 1 and 4.5 out of every 1000 live births. It is usually associated with arthrogryposis and Moebius syndrome with the latter two being more difficult to treat as they require aggressive surgery to achieve a plantigrade foot. We therefore ask what is the evidence level and grade of recommendation of the Ponseti method to treat syndromic talipes equinovarus resulting from arthrogryposis and Moebius syndrome. METHODS: Systematic review according to the recommendations of the Cochrane group identifying medical subheadings (MeSH) and of the Boolean method to identify the articles that met the selection criteria through the search of primary sources such as OVID, Cochrane, EBSCOhost, Elsevier, Medigraphic. RESULTS: A total of six papers met the selection criteria through the search in the primary sources. Five of them address the treatment of adduct CTE with the Ponseti method in patients with arthrogryposis, and one in patients with Moebius. Evidence levels and grades of recommendation of these papers were: IV-D (3), III-D (1) y II (B). CONCLUSIONS: The Ponseti method is an first-line treatment for arthrogryposis and Moebius syndrome. It is unexpensive, non-invasive and does not require a physician to perform it (however, it does require trained staff). Its use is recommended as it avoids extensive surgeries and medical complications that go beyond the hospitals economic possibilities.


ANTECEDENTES: El pie equino varo aducto congénito (PEVAC) es una malformación musculoesquelética común que afecta de uno a 4.5 de cada 1,000 nacidos vivos; se asocia de manera común a artrogriposis y síndrome de Moebius; éstos son más difíciles de tratar y requieren de tratamientos quirúrgicos agresivos para lograr un pie plantígrado; por lo tanto, ¿cuál es el nivel de evidencia y grado de recomendación del uso del método de Ponseti en el pie equino varo sindromático por artrogriposis y síndrome de Moebius? MÉTODOS: Estudio de diseño de revisión sistemática de acuerdo a las recomendaciones del grupo Cochrane por medio de la identificación de Medical Subject Headings (MeSH) y del método booleano para ubicar artículos que cumplieran con los criterios de selección mediante búsqueda de fuentes primarias como OVID, Cochrane, EBSCOhost, Elsevier, Medigraphic. RESULTADOS: En total, seis artículos cumplieron con los criterios de selección a través de la búsqueda de fuentes primarias: cinco de ellos sobre el tratamiento del PEVAC con método de Ponseti en pacientes con artrogriposis y uno para pacientes con Moebius. Se encontraron artículos con niveles de evidencia y grado de recomendación: IV-D (3), III-D (1) y II (B). CONCLUSIONES: El método de Ponseti es un tratamiento inicial en artrogriposis y síndrome de Moebius; es barato, no invasivo y no requiere de un médico para poderse realizar (pero sí un personal capacitado); se recomienda su uso para evitar cirugías extensas y complicaciones médicas que trascienden al orden económico intrahospitalario.


Asunto(s)
Artrogriposis , Pie Equinovaro , Síndrome de Mobius , Artrogriposis/cirugía , Moldes Quirúrgicos , Pie Equinovaro/cirugía , Humanos , Lactante , Síndrome de Mobius/cirugía , Procedimientos Ortopédicos , Resultado del Tratamiento
5.
Genet Mol Res ; 16(3)2017 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-28973746

RESUMEN

Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells that mediate non-visual responses to light. The aim of this study was to describe and analyze melanopsin gene expression in the rabbit retina at different ages and compare its expression with the prototypic gene of retinal ganglion cells (Thy-1 gene). Expression levels of OPN4, Thy-1, and GADPH genes were measured by real-time PCR at 3, 4, 8, 11, 12, 17, 19, 20, 23, 27, 32, and 47 postnatal days. We also regrouped the days before and after day 12 of life (pre-photic and post-photic stage, respectively). Average expression of the OPN4 gene between days was similar (P = 0.713), but was statistically different in the Thy-1 gene (P = 0.004). Also, no significant differences were found in OPN4 gene expression pre-photic and post-photic stage (P = 0.629); however, Thy-1 expression was higher in the pre-photic stage, almost double, than in the post-photic stage, with significant differences (P = 0.001). This is the first report describing OPN4 gene expression in the rabbit retina at different ages. We demonstrated that the OPN4 gene is constantly expressed at all early stages, even before the onset of photoentrainment by the pups and that Thy-1 and OPN4 gene expressions are out of phase.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Retina/metabolismo , Opsinas de Bastones/metabolismo , Animales , ARN Mensajero/genética , ARN Mensajero/metabolismo , Conejos , Retina/crecimiento & desarrollo , Opsinas de Bastones/genética , Antígenos Thy-1/genética , Antígenos Thy-1/metabolismo
6.
Food Chem ; 159: 267-72, 2014 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-24767054

RESUMEN

Bioactive compounds have become very important in the food and pharmaceutical markets leading research interests seeking efficient methods for extracting these bioactive substances. The objective of this research is to implement preparative scale obtention of mangiferin and lupeol from mango fruit (Mangifera indica L.) of autochthonous and Ataulfo varieties grown in Nayarit, using emerging extraction techniques. Five extraction techniques were evaluated: maceration, Soxhlet, sonication (UAE), microwave (MAE) and high hydrostatic pressures (HHP). Two maturity stages (physiological and consumption) as well as peel and fruit pulp were evaluated for preparative scale implementation. Peels from Ataulfo mango at consumption maturity stage can be considered as a source of mangiferin and lupeol using the UEA method as it improves extraction efficiency by increasing yield and shortening time.


Asunto(s)
Métodos Analíticos de la Preparación de la Muestra/métodos , Mangifera/química , Triterpenos Pentacíclicos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Xantonas/aislamiento & purificación , Frutas/química , Triterpenos Pentacíclicos/análisis , Extractos Vegetales/análisis , Xantonas/análisis
7.
Arq. bras. med. vet. zootec ; Arq. bras. med. vet. zootec. (Online);65(5): 1434-1440, out. 2013. tab
Artículo en Portugués | LILACS | ID: lil-689762

RESUMEN

Com este trabalho objetivou-se avaliar a influência de diferentes fotoperíodos sobre parâmetros fisiológicos relacionados ao estresse em alevinos de tilápia-do-nilo (Oreochromis niloticus). Foi utilizado um delineamento inteiramente casualizado, com cinco tratamentos (0L; 6L; 12L; 18L; 24L) e quatro repetições, sendo o aquário a unidade experimental. Cento e sessenta alevinos de tilápia, 3,21±0,05g e 4,35±0,07cm, foram distribuídos em 20 aquários de 20 litros, em sistema de recirculação com temperatura controlada em 27oC e densidade de oito peixes por aquário. Por um período de 75 dias, a alimentação foi realizada duas vezes ao dia com ração extrusada contendo 40% de proteína bruta. Ao final do período experimental, os dados de crescimento, sobrevivência, cortisol, glicose e hematócrito foram submetidos à análise de variância e, posteriormente, em caso de significância (P<0,05), foi realizado um teste Tukey a 5% para comparação das médias. A manipulação do fotoperíodo demonstra não alterar a homeostase dos alevinos, uma vez que não há diferença sobre a sobrevivência, glicose sanguínea, hematócrito e cortisol plasmático (P>0,05).


The objective of this study was to evaluate the influence of different photoperiods on physiological parameters related to stress in Nile tilapia fingerlings (Oreochromis niloticus). A completely randomized design with five treatments (0L, 6L, 12L, 18L, 24L) and four replications was used, and the aquarium as the experimental unit. One hundred and sixty tilapia fingerlings, 3.21±0.05g and 4.35±0.07cm were distributed in 20 aquariums of 20L in a recirculation system with temperature controlled at 27 º C and density of eight fish per aquarium. Feeding was performed twice daily with extruded feed containing 40% crude protein, for a period of 75 days. At the end of experimental period, the data of survival, cortisol, glucose and hematocrit were subjected to analysis of variance and, subsequently, in case of significance (P<0.05) a Tukey test 5% was performed to compare means. Manipulation of photoperiod shows no alteration in the homeostasis of juveniles, since there is no difference in survival, blood glucose, hematocrit and plasma cortisol (P>0.05).


Asunto(s)
Animales , Cíclidos , Hidrocortisona/fisiología , Homeostasis/fisiología , Fotoperiodo , Glucosa
8.
Arq. bras. med. vet. zootec ; 65(5): 1434-1440, out. 2013. tab
Artículo en Portugués | VETINDEX | ID: vti-10057

RESUMEN

Com este trabalho objetivou-se avaliar a influência de diferentes fotoperíodos sobre parâmetros fisiológicos relacionados ao estresse em alevinos de tilápia-do-nilo (Oreochromis niloticus). Foi utilizado um delineamento inteiramente casualizado, com cinco tratamentos (0L; 6L; 12L; 18L; 24L) e quatro repetições, sendo o aquário a unidade experimental. Cento e sessenta alevinos de tilápia, 3,21±0,05g e 4,35±0,07cm, foram distribuídos em 20 aquários de 20 litros, em sistema de recirculação com temperatura controlada em 27oC e densidade de oito peixes por aquário. Por um período de 75 dias, a alimentação foi realizada duas vezes ao dia com ração extrusada contendo 40% de proteína bruta. Ao final do período experimental, os dados de crescimento, sobrevivência, cortisol, glicose e hematócrito foram submetidos à análise de variância e, posteriormente, em caso de significância (P<0,05), foi realizado um teste Tukey a 5% para comparação das médias. A manipulação do fotoperíodo demonstra não alterar a homeostase dos alevinos, uma vez que não há diferença sobre a sobrevivência, glicose sanguínea, hematócrito e cortisol plasmático (P>0,05).(AU)


The objective of this study was to evaluate the influence of different photoperiods on physiological parameters related to stress in Nile tilapia fingerlings (Oreochromis niloticus). A completely randomized design with five treatments (0L, 6L, 12L, 18L, 24L) and four replications was used, and the aquarium as the experimental unit. One hundred and sixty tilapia fingerlings, 3.21±0.05g and 4.35±0.07cm were distributed in 20 aquariums of 20L in a recirculation system with temperature controlled at 27 º C and density of eight fish per aquarium. Feeding was performed twice daily with extruded feed containing 40% crude protein, for a period of 75 days. At the end of experimental period, the data of survival, cortisol, glucose and hematocrit were subjected to analysis of variance and, subsequently, in case of significance (P<0.05) a Tukey test 5% was performed to compare means. Manipulation of photoperiod shows no alteration in the homeostasis of juveniles, since there is no difference in survival, blood glucose, hematocrit and plasma cortisol (P>0.05).(AU)


Asunto(s)
Animales , Fotoperiodo , Cíclidos/anatomía & histología , Cíclidos/fisiología , Homeostasis/fisiología , Hidrocortisona/fisiología , Glucosa
9.
Carbohydr Polym ; 98(1): 1018-24, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23987442

RESUMEN

High pressure processing (HPP) technology was used to modify the structural composition of sugarcane bagasse. The effect of pressure (0, 150 and 250 MPa), time (5 and 10 min) and temperature (25 and 50 °C) as well as the addition of phosphoric acid, sulfuric acid and NaOH during the HPP treatment were assessed in terms of compositional analysis of the lignocellulosic fraction, structural changes and crystallinity of the bagasse. The effect of HPP pretreatment on the bagasse structure was also evaluated on the efficiency of the enzymatic hydrolysis of bagasse. Results showed that 68.62 and 45.84% of the hemicellulose fraction was degraded by pretreating at 250 MPa with sulfuric and phosphoric acids, respectively. The removal of lignin (54.10%) was higher with the HPP-NaOH treatment. The compacted lignocellulosic structure of the raw bagasse was modified by the HPP treatments and showed few cracks, tiny holes and some fragments flaked off from the surface. Structural changes were higher at 250 MPa and 50 °C. The X ray diffraction (XRD) patterns of the raw bagasse showed a major diffraction peak of the cellulose crystallographic 2θ planes ranging between 22 and 23°. The distribution of the crystalline structure of cellulose was affected by increasing the pressure level. The HPP treatment combined with NaOH 2% led to the higher glucose yield (25 g/L) compared to the combination of HPP with water and acids (>5 g/L). Results from this work suggest that HPP technology may be used to pretreat sugarcane bagasse.


Asunto(s)
Celulosa/química , Presión , Saccharum/química , Celulasa/metabolismo , Celulosa/metabolismo , Hidrólisis , Lignina/química , Temperatura
10.
Bioresour Technol ; 118: 603-6, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22704830

RESUMEN

Phytase production by Aspergillus niger F3 by solid state fermentation (SSF) on citrus peel was evaluated at pilot scale under different aeration conditions. The best airflow intensity was 1 VkgM (Lair kg medium(-1) min(-1)), which allowed to produce 65 units of phytases per gram in dry basis (65 Ug(-1) d.b.) as it removed the metabolic heat generated by the microorganism, Agitation did not improve heat removal. Airflow intensity was considered as scale-up criterion. When the airflow intensity was maintained at 1 VkgM for SSF with 2 and 20 kg of medium, the kinetics parameters for biomass and enzyme concentration at the end of fermentation differed by less than 2. The air flow intensity was required to maintain the temperature and cool the SSF and to provide oxygen for microbial growth. Air flow intensity is a key a factor that must be considered when scale-up of SSF is attempted.


Asunto(s)
6-Fitasa/biosíntesis , Movimientos del Aire , Aspergillus niger/enzimología , Biotecnología/métodos , Fermentación/fisiología , Aerobiosis , Calor , Cinética
11.
Bioresour Technol ; 102(22): 10657-62, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21945204

RESUMEN

Solid-state fermentation (SSF) is defined as the growth of microbes without a free-flowing aqueous phase. The feasibility of using a citrus peel for producing pectinase and xylanase via the SSF process by Aspergillus niger F3 was evaluated in a 2 kg bioreactor. Different aeration conditions were tested to optimize the pectinase and xylanase production. The best air flow intensity was 1 V kg M (volumetric air flow per kilogram of medium), which allowed a sufficient amount of O2 for the microorganism growth producing 265 U/g and 65 U/g pectinases and xylanases, respectively. A mathematical model was applied to determine the different kinetic parameters related to SSF. The specific growth rate and biomass oxygen yield decreased during fermentation, whereas an increase in the maintenance coefficient for the different employed carbon sources was concurrently observed.


Asunto(s)
Aspergillus niger/enzimología , Biotecnología/métodos , Endo-1,4-beta Xilanasas/biosíntesis , Fermentación , Poligalacturonasa/biosíntesis , Aerobiosis , Aire , Biomasa , Reactores Biológicos/microbiología , Dióxido de Carbono/metabolismo , Citrus/química , Cinética , Consumo de Oxígeno
12.
Acta Ortop Mex ; 25(3): 188-94, 2011.
Artículo en Español | MEDLINE | ID: mdl-22512117

RESUMEN

Infantile idiopathic scoliosis (IIS) represents one of the most severe forms of scoliosis. At the time of skeletal maturity the untreated progressive curves are usually over 100 degrees and have an important rotational component. That is why the natural course of IIS is thought to occur until the time that patients are treated, around 10 years of age. A close follow-up is recommended in these cases and, if necessary, starting active treatment in cases of progression. Patients who started treatment at an earlier age had better results than those who started at around 2 years of age. The overall risk of complications of IIS during the treatment period using a construct with rods is 58%. This percent decreases if implant placement is delayed as much as possible until the time of the initial surgery, at around 6 years of age, besides using a double rod instead of a single rod (10 vs 27%) and limiting the number of lengthening procedures (each subsequent lengthening results in a 24% increase in the risk of complications). The complications rate is moderate, but manageable. At present the use of a double rod with scheduled serial lengthenings seems to offer better results than the use of a single rod, due to its better capacity to control the spine. Early-onset scoliosis should be distinguished from other types of scoliosis. There are relevant doubts concerning the etiology and treatment, which should be addressed specifically.


Asunto(s)
Escoliosis/terapia , Edad de Inicio , Femenino , Humanos , Lactante , Masculino
13.
Rev Esp Anestesiol Reanim ; 53(1): 46-9, 2006 Jan.
Artículo en Español | MEDLINE | ID: mdl-16475639

RESUMEN

Over the past 10 years, the application of high frequency oscillatory ventilation (HFOV) has been extended beyond the neonatal period. The technique is now used in various respiratory disease settings when conventional mechanical ventilation fails. Even though HFOV has become increasingly routine in some pediatric intensive care units, familiarity with it is still limited among anesthesiologists and surgeons and it is not often applied during surgery. We report our experience using HFOV during thoracic surgery on 2 pediatric patients, one aged 5 years and the other aged 1 month. The respective surgical procedures were to close a bronchopleural fistula and to obtain a lung biopsy in order to provide guidance for limiting therapeutic intervention. In both cases the procedure was performed without adverse effects and allowed medical interventions to be carried out. We conclude that it is possible to perform thoracic surgery in pediatric patients undergoing HFOV. This ventilation mode can be useful during surgery and teams that care for critically ill children should be familiar with the equipment.


Asunto(s)
Biopsia , Fístula Bronquial/cirugía , Fístula/cirugía , Ventilación de Alta Frecuencia , Cuidados Intraoperatorios/métodos , Pulmón/patología , Enfermedades Pleurales/cirugía , Síndrome de Dificultad Respiratoria del Recién Nacido/terapia , Síndrome de Dificultad Respiratoria/terapia , Barotrauma/etiología , Preescolar , Resultado Fatal , Ventilación de Alta Frecuencia/efectos adversos , Humanos , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Cuidados Intraoperatorios/efectos adversos , Masculino , Insuficiencia Multiorgánica/complicaciones , Neumotórax/etiología , Enfisema Pulmonar/etiología , Proteína B Asociada a Surfactante Pulmonar/deficiencia , Respiración Artificial , Síndrome de Dificultad Respiratoria/cirugía , Síndrome de Dificultad Respiratoria del Recién Nacido/cirugía , Rotura Espontánea , Choque Séptico/complicaciones , Toracotomía
15.
Biotechnol Prog ; 17(6): 1065-70, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11735442

RESUMEN

Studies were carried out to evaluate solid-state fermentation (SSF) for the upgradation of the nutritional quality of coffee husk by degrading the caffeine and tannins present in it. SSF was carried out by Aspergillus niger LPBx in a glass column fermenter using factorial design experiments and surface response methodology to optimize bioprocess parameters such as the substrate pH and moisture content and aeration rate. The first factorial design showed that the moisture content of the substrate and aeration rate were significant factors for the degradation of toxic compounds, which was confirmed by the second factorial design too. The kinetic study showed that the degradation of toxic compounds was related to the development of the mold and its respiration and also to the consumption of the reducing sugars present in coffee husk. From the values obtained experimentally for the oxygen uptake rate and CO(2) evolved, the system determined a biomass yield (Y(x/o)) of 3.811 (g of biomass).(g of consumed O(2))(-1) and a maintenance coefficient (m) of 0.0031 (g of consumed O(2)).(g biomass of biomass)(-1).h(-1). The best results on the degradation of caffeine (90%) and tannins (57%) were achieved when SSF was carried out with a 30 mL.min(-1) aeration rate using coffee husk having a 55% initial moisture content. The inoculation rate did not affect the metabolization of the toxic compounds by the fungal culture. After SSF, the protein content of the husk was increased to 10.6%, which was more than double that of the unfermented husk (5.2%).


Asunto(s)
Aspergillus niger/metabolismo , Café/química , Valor Nutritivo , Algoritmos , Biomasa , Cafeína/química , Medios de Cultivo , Fermentación , Cinética , Modelos Biológicos , Taninos/química
16.
J Theor Biol ; 205(4): 563-79, 2000 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-10931752

RESUMEN

We perform a perturbation analysis (comparative statics) of how optimal reproductive effort and per offspring investment are jointly affected by different selective factors. The factors considered are: (1) mortality sources, classified according to affected stage (juvenile or adult) and to its nature (avoidable or unavoidable), and (2) resource (energy) availability for the adult individual. The joint approach reveals both direct and indirect effects of each selective pressure. These interactive effects spring from the nonlinearity of reproductive expenditure, separated into a part devoted to endowing offspring (provisioning cost) and another part invested to make reproduction possible (requisite cost). The latter is envisioned as a reverse sigmoid function of fecundity (most models, so far, have considered only the first kind of cost). The indirect effects have the consequence of enlarging the class of selective pressures that can induce changes of offspring size and clutch size, as compared with current explanations. So, they illuminate new causes for some effects, and show new effects for some well-known selective causes. Several joint patterns in the two variables, shown by animals and plants in the field, can thus be given more appropriate interpretations than traditional, piecewise, ones.


Asunto(s)
Evolución Biológica , Ambiente , Modelos Estadísticos , Reproducción/fisiología , Animales , Metabolismo Energético , Mortalidad , Fenómenos Fisiológicos de las Plantas
17.
An Otorrinolaringol Ibero Am ; 23(4): 397-400, 1996.
Artículo en Español | MEDLINE | ID: mdl-8967562

RESUMEN

A case occurring in a 62 year-old male with a xantomatous infiltrate taking the pharyngolarynx is reported. Basic features of xantomatosis are described as other manifestations encountered in the ENT-area.


Asunto(s)
Laringe/fisiopatología , Faringe/fisiopatología , Xantomatosis/fisiopatología , Humanos , Laringe/cirugía , Masculino , Persona de Mediana Edad , Faringe/cirugía , Xantomatosis/cirugía
19.
An Otorrinolaringol Ibero Am ; 22(1): 67-73, 1995.
Artículo en Español | MEDLINE | ID: mdl-7710013

RESUMEN

Kikuchi-Fujimoto disease (KFD) is a rare entity of uncertain cause which commonly presents as a lymphoadenopathy unresponsive to antibiotic therapy. Although usually it follows a benign self-limited course KFD has been repeatedly misdiagnosed as lymphoma. With this new case data about the etiology and clinical trend of KFD are added. Review of the literature.


Asunto(s)
Linfadenitis/diagnóstico , Otolaringología , Niño , Diagnóstico Diferencial , Femenino , Humanos
20.
Pediatr Dermatol ; 10(1): 69-70, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8493174

RESUMEN

An infant had a 3 x 1.5-cm congenital, slow-growing, lobulated tumor below the right inferior eyelid. The mass transilluminated, and needle aspiration yielded tears. Dacryocystography showed a large cystic area connected with the lower lacrimal canaliculum. Histologically, the tumor proved to be a dermoid cyst. This association has not been reported previously. Surgical excision and suture of the pedicule resulted in permanent cure.


Asunto(s)
Quiste Dermoide/congénito , Neoplasias de los Párpados/congénito , Aparato Lagrimal/anomalías , Quiste Dermoide/complicaciones , Quiste Dermoide/cirugía , Neoplasias de los Párpados/complicaciones , Neoplasias de los Párpados/cirugía , Femenino , Humanos , Lactante , Aparato Lagrimal/metabolismo , Aparato Lagrimal/cirugía
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