Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
1.
Bull Entomol Res ; 107(1): 21-31, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27819207

RESUMEN

Chorthippus vagans is a common species of Gomphocerinae (Orthoptera) on the Iberian Peninsula. It is endangered in Central Europe where information about its ecological requirements is available; however, aspects of its biology are almost unknown in Mediterranean ecosystems, where it is widespread and common. The focus of this study was to determine how C. vagans adjusts its biology to environmental features of this ecosystem and to interpret how it may be affected by the ecological changes related to the re-vegetation programme linked to the construction of the Breña dam (SW Spain). The research parameters included the autoecology, feeding response and some aspects of reproduction of this species in the Southern Iberian Peninsula. To determine the local distribution and phenology of C. vagans, monthly samplings were conducted (2007-2010) in 12 sampling plots. For the food selection tests, ten nymphs and ten adults were placed individually in insectaries under controlled conditions. Grasses (Lolium sp.) and shrubs (Cistus sp.) were supplied ad libitum in two types of tests, monospecific and mixed diet. The reproductive biology was analysed by both observations of anatomical structures (integument, bristles, tibial spines, tarsal claws and mandibles) and ovarian dissections of 29 females and in laboratory rearing experiments with 15 pairs of adults. The results indicate that C. vagans shows an extended activity period which peaks at the end of summer. It is a polyphagous grasshopper, although adults show a slight preference for grasses. In addition, it is a univoltine species with spring-summer breeding activity.


Asunto(s)
Saltamontes/fisiología , Animales , Conducta Alimentaria , Femenino , Saltamontes/crecimiento & desarrollo , Masculino , Ninfa/crecimiento & desarrollo , Ninfa/fisiología , Reproducción , Estaciones del Año , España
2.
Phys Rev E Stat Nonlin Soft Matter Phys ; 77(3 Pt 2): 036213, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18517491

RESUMEN

We demonstrate that the dynamics toward and within the Feigenbaum attractor combine to form a q -deformed statistical-mechanical construction. The rate at which ensemble trajectories converge to the attractor (and to the repellor) is described by a q entropy obtained from a partition function generated by summing distances between neighboring positions of the attractor. The values of the q indices involved are given by the unimodal map universal constants, while the thermodynamic structure is closely related to that formerly developed for multifractals. As an essential component in our demonstration we expose, in great detail, the features of the dynamics of trajectories that either evolve toward the Feigenbaum attractor or are captured by its matching repellor. The dynamical properties of the family of periodic superstable cycles in unimodal maps are seen to be key ingredients for the comprehension of the discrete scale invariance features present at the period-doubling transition to chaos. Elements in our analysis are the following. (i) The preimages of the attractor and repellor of each of the supercycles appear entrenched into a fractal hierarchical structure of increasing complexity as period doubling develops. (ii) The limiting form of this rank structure results in an infinite number of families of well-defined phase-space gaps in the positions of the Feigenbaum attractor or of its repellor. (iii) The gaps in each of these families can be ordered with decreasing width in accordance with power laws and are seen to appear sequentially in the dynamics generated by uniform distributions of initial conditions. (iv) The power law with log-periodic modulation associated with the rate of approach of trajectories toward the attractor (and to the repellor) is explained in terms of the progression of gap formation. (v) The relationship between the law of rate of convergence to the attractor and the inexhaustible hierarchy feature of the preimage structure is elucidated. (vi) A "mean field" evaluation of the atypical partition function, a thermodynamic interpretation of the time evolution process, and a crossover to ordinary exponential statistics are given. We make clear the dynamical origin of the anomalous thermodynamic framework existing at the Feigenbaum attractor.

3.
J Agric Food Chem ; 47(8): 3297-302, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10552649

RESUMEN

The effect of an acceleration assay, carried out with a periodic aeration and an increased surface/volume ratio, on various aroma compounds of "fino" Sherry wines aging under a veil of a pure culture of Saccharomyces cerevisiae race capensis G1 flor film yeast was studied. The results were subjected to multifactor analysis of variance, and the compounds simultaneously depending on acceleration conditions and aging time at p < 0.01 were subjected to principal component analysis. The first component, accounting for 86.14% of the overall variance, was mainly defined by acetaldehyde and its derivatives 1,1-diethoxyethane and acetoin. These compounds reached higher concentrations in accelerated aging wines in a shorter time than they did in control wines, and no browning problems were detected. Taking into account that these compounds can be used as indicators for biological aging of "fino" Sherry wines, the acceleration condition assayed can be applied to shorten the time of this process.


Asunto(s)
Manipulación de Alimentos/métodos , Odorantes/análisis , Vino/análisis , Alcoholes/análisis , Análisis de Varianza , Ésteres/análisis , Fermentación , Microbiología de Alimentos , Saccharomyces cerevisiae
4.
Int J Anal Chem ; 20102010.
Artículo en Inglés | MEDLINE | ID: mdl-20689702

RESUMEN

The aroma of Fino sherry wines produced by industrial biological aging for 0, 1.5, 2.5, 4.5, and 6 years in the Montilla-Moriles region (southern Spain) was studied by gas chromatography-olfactometry. The aroma sensations detected by 3 trained sniffers were classified according to their odor descriptors into 8 odorant series (fruity, empyreumatic, chemical, fatty, balsamic, vegetable, floral, and spicy), describing the aroma profile of the studied wines. The results showed 47 detected odors in the unaged wines, 50 in the 1.5-years-old wines and 59, 61 and 69 in the wines aged 2.5, 4.5, and 6 years, respectively. According to the frequency of the perceived aromas, the fruity and empyreumatic series were the most characteristic odorant series. By exception of chemical, floral and balsamic series without changes during aging of the wines, the remainder series increased their participation during the aging, mainly the fruity, empyreumatic, and fatty series.

5.
Rev. méd. Chile ; 131(9): 965-972, sept. 2003.
Artículo en Español | LILACS | ID: lil-356017

RESUMEN

BACKGROUND: Nodular thyroid disease is a very common disorder with a low frequency of malignancy. The most accurate diagnostic test is fine needle aspiration biopsy (FNAB) of nodules with cytological analysis of the sample. However, this procedure has some limitations in the diagnosis of follicular and papillary thyroid carcinoma. AIM: To detect mRNA from specific malignancy markers in thyroid nodules and to evaluate their potential correlation with cytological and pathological diagnosis. PATIENTS AND METHODS: In 20 patients with thyroid nodules FNAB was performed prior to surgery. The main part of the FNAB sample was used to perform classical cytology. In the remaining of the sample were detected MUC-1, CD26, galectin-3 and TSH receptor mRNAs by RT-PCR technique. RESULTS: Eight patients had positive cytology for papillary cancer, which was confirmed by pathology. Nine had suspicious or non conclusive cytological findings and 3 were negative for neoplastic cells; all 12 were pathologically benign. We detected TSH receptor and galectin-3 mRNA in almost all benign and malignant nodules. MUC-1 was present in 5/8 papillary carcinoma (62.5%), and 1/12 benign nodules (8.3%). CD26 was detected in 7/8 papillary carcinomas but also in 8/12 benign nodules. CONCLUSIONS: RT-PCR can be performed in very small samples of thyroid tissue to detect several mRNA markers. MUC-1 can be a potentially useful marker of malignancy in thyroid nodules. It can be detected by RT-PCR as a complementary technique in the diagnostic evaluation of thyroid nodules.


Asunto(s)
Humanos , Carcinoma Papilar/química , Biomarcadores de Tumor/análisis , Nódulo Tiroideo/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Carcinoma Papilar/patología , Electroforesis en Gel de Agar , Estudios Prospectivos , Nódulo Tiroideo/patología , ARN Mensajero/análisis
6.
Rev. argent. dermatol ; 71(3): 170-3, jul.-set. 1990. ilus
Artículo en Español | LILACS | ID: lil-96305

RESUMEN

Las pápulas y placas urticarianas pruriginosas del embarazo (PPUPE) constituyen una afección benigna de la segunda mitad de la gestación, que es necesario diferenciar de las formas iniciales del herpes gestationis, de muy distinto pronóstico. Es imprescindible para ello el empleo de métodos inmunohistológicos, en que la ausencia o presencia de C3 en la membrana basal epidérmica confirma o excluye respectivamente, la PPUPE. Se presenta el caso de una paciente primigrávida de 19 años, que refiere prurito severo, con lesiones típicas de PPUPE, que remiten con corticoterapia local; el laboratorio de rutina era normal y la histología de las lesiones inespecifica. Se confirmó el diagnóstico de PPUPE por ausencia de C3 en inmunomarcación. La tinción con C3 de algunos vasos dérmicos nos permite excluir un falso negativo


Asunto(s)
Embarazo , Adulto , Humanos , Femenino , Complicaciones del Embarazo , Prurito/diagnóstico , Urticaria/diagnóstico , Diagnóstico Diferencial , Prurito/tratamiento farmacológico , Urticaria/tratamiento farmacológico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA