Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Sci Rep ; 11(1): 13342, 2021 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-34172777

RESUMEN

The spatio-temporal variability of fish distribution is important to better manage and protect the populations of endangered species. In this sense, the vertical movements of a vulnerable and protected species, Sciaena umbra, were assessed in a marine protected area (the Réserve Naturelle Marine de Cerbère-Banyuls, south of France) to study the variability of their bathymetric distribution at different time scales. Twenty adults were marked with acoustic transmitters and acoustically monitored over 2.5 years. This revealed that some individuals remained at shallow waters (< 8 m) all year round, while others presented vertical segregation at deeper waters during the cold months (mean depth of 22.5 ± 0.04 m) and all aggregated in shallow waters during the warm months. The brown meagre was more active during the night, except in June and July when peaks of activity were observed at dusk. These patterns are likely associated with foraging and reproductive behavior during the cold and warm periods, respectively, and likely regulated by water temperature and the depth of the thermocline. Here, we provide valuable information on when and where in the water column critical periods of S. umbra life cycle are expected to occur, which should be considered in management and protection plans.


Asunto(s)
Cordados/fisiología , Peces/fisiología , Animales , Conservación de los Recursos Naturales/métodos , Ecosistema , Estaciones del Año , Temperatura
2.
Proc Biol Sci ; 288(1951): 20210458, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-34004134

RESUMEN

How far do marine larvae disperse in the ocean? Decades of population genetic studies have revealed generally low levels of genetic structure at large spatial scales (hundreds of kilometres). Yet this result, typically based on discrete sampling designs, does not necessarily imply extensive dispersal. Here, we adopt a continuous sampling strategy along 950 km of coast in the northwestern Mediterranean Sea to address this question in four species. In line with expectations, we observe weak genetic structure at a large spatial scale. Nevertheless, our continuous sampling strategy uncovers a pattern of isolation by distance at small spatial scales (few tens of kilometres) in two species. Individual-based simulations indicate that this signal is an expected signature of restricted dispersal. At the other extreme of the connectivity spectrum, two pairs of individuals that are closely related genetically were found more than 290 km apart, indicating long-distance dispersal. Such a combination of restricted dispersal with rare long-distance dispersal events is supported by a high-resolution biophysical model of larval dispersal in the study area, and we posit that it may be common in marine species. Our results bridge population genetic studies with direct dispersal studies and have implications for the design of marine reserve networks.


Asunto(s)
Flujo Génico , Genética de Población , Animales , Humanos , Larva/genética , Mar Mediterráneo
3.
Mar Pollut Bull ; 126: 31-42, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29421103

RESUMEN

High abundances of juvenile fish in certain ports suggest they might provide alternative nursery habitats for several species. To further investigate this possibility, post-settlement growth, metal uptake and body condition were estimated in 127 juveniles of two seabream species, collected in 2014-15, inside and outside the highly polluted ports of the Bay of Toulon. This showed that differences in local pollution levels (here in Hg, Cu, Pb and Zn) are not consistently mirrored within fish flesh. Muscle metal concentrations, below sanitary thresholds for both species, were higher in ports for Cu, Pb and V only. Otherwise, fish muscle composition principally differed by species or by year. Juvenile growth and condition were equivalent at all sites. Higher prey abundance in certain ports might therefore compensate the deleterious effects of pollution, resulting in similar sizes and body conditions for departing juvenile fish than in nearby natural habitats.


Asunto(s)
Metales Pesados/análisis , Dorada , Contaminantes Químicos del Agua/análisis , Animales , Ecosistema , Monitoreo del Ambiente , Músculos/química , Dorada/crecimiento & desarrollo , Dorada/metabolismo
4.
J Fish Biol ; 91(5): 1491-1509, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28980318

RESUMEN

A total of 38 individuals of the heavily exploited little gulper shark Centrophorus uyato were collected from Lebanese coastal waters using bottom longlines and trammel nets of different meshes at depths ranging from 115 to 600 m between May 2013 and February 2014. Their total lengths were between 45 and 94 cm and their total mass was from 870 to 6700 g. The sex ratio was not significantly different from 1:1, with 20 males and 18 females, but bathymetric sexual segregation occurred. Catch per net setting (CNS) was used as a relative abundance index to detect spatial distribution; trammel nets showed largest CNS ranging from 4·9 to 5·45 kg per unit effort in the north and south, at depths from 120 to 200 m, during spring and summer. The mass-length relationships demonstrated negative allometric growth (b < 3) (males: MT = 0.3585LT2·071 , r2 = 0·94; females: MT = 0.0239LT2·735 , r2 = 0·64). The condition factor as well as the gonado-somatic and hepato-somatic indices of C. uyato in the study area were also calculated. The results are discussed in relation to the distribution, growth and reproduction as well as the management of C. uyato.


Asunto(s)
Tiburones/fisiología , Animales , Biodiversidad , Femenino , Explotaciones Pesqueras , Líbano , Masculino , Densidad de Población , Reproducción , Alimentos Marinos , Estaciones del Año , Razón de Masculinidad , Tiburones/clasificación , Tiburones/crecimiento & desarrollo
5.
J Fish Biol ; 88(4): 1441-59, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26928654

RESUMEN

This study focuses on the population biology of the common guitarfish Rhinobatos rhinobatos, a cartilaginous fish listed as Endangered in the International Union for the Conservation of Nature (IUCN) Red List. Between December 2012 and January 2014, 67 individuals were collected by bottom longlining in coastal Lebanese marine waters at different ports at depths ranging from 10 to 110 m. The total length (L(T)) of the specimens ranged from 50 to 143 cm, and the mean ± s.d. was 76.2 ± 19.7 cm. The most common L(T) classes were between 60 and 70 cm. The total mass of the specimens ranged from 410 to 10,000 g, and the mean ± s.d. was 1841 ± 1987 g. A total of 34 males and 33 females were collected, and the sex ratio was not significantly different from 1:1. The mass and L(T) relationship showed positive allometric growth (b = 3.096 and r(2) = 0.99), and the mean ± s.d. L(T) at which 50% of the individuals were sexually mature was 84.73 ± 5.81 cm for females and 78.57 ± 4.88 cm for males. The gonado-somatic and hepato-somatic indices were determined along with a condition factor, and parturition appeared to occur in winter. The primary prey items found in the fish stomachs during the autumn and winter seasons were Penaeidae. The results of this study will help to parameterize models of the population dynamics for this exploited fish stock to ensure the long-term sustainability of its fishery.


Asunto(s)
Especies en Peligro de Extinción , Rajidae , Animales , Tamaño Corporal , Femenino , Explotaciones Pesqueras , Contenido Digestivo , Líbano , Masculino , Mar Mediterráneo , Dinámica Poblacional , Estaciones del Año , Razón de Masculinidad , Maduración Sexual
6.
Neuroscience ; 307: 281-301, 2015 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-26341909

RESUMEN

INTRODUCTION: Freezing of gait (FoG) is a debilitating gait disorder in Parkinson's disease (PD). In advanced PD patients with FoG, the supraspinal locomotor network may be dysregulated (relative to similar patients without FoG) during gait. Here, we sought to characterize the metabolism of locomotor networks involved in FoG. METHODS: Twenty-two PD patients (11 with off-drug FoG and 11 without) each underwent two [(18)F]-fluorodeoxyglucose PET brain scans in the off-drug state: one at rest and another during radiotracer uptake while performing a standardized gait trajectory that incorporated the usual triggers for FoG. RESULTS: For the 11 freezers, FoG was present for 39% (± 23%) of the time during the gait trajectory. The FoG-associated abnormalities were characterized by (i) hypometabolism in frontal regions (the associative premotor, temporopolar and orbitofrontal areas, i.e. Brodmann areas 6 and 8), (ii) hypermetabolism in the paracentral lobule (Brodmann area 5), and (iii) deregulation of the basal ganglia output (the globus pallidus and the mesencephalic locomotor region). CONCLUSION: FoG during a real gait task was associated with impaired frontoparietal cortical activation, as characterized by abnormally low metabolic activity of the premotor area (involved in the indirect locomotor pathway) and abnormally high metabolic activity of the parietal area (reflecting the harmful effect of external cueing).


Asunto(s)
Encéfalo/metabolismo , Trastornos Neurológicos de la Marcha/etiología , Enfermedad de Parkinson/patología , Anciano , Encéfalo/diagnóstico por imagen , Análisis por Conglomerados , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Enfermedad de Parkinson/diagnóstico por imagen , Tomografía de Emisión de Positrones , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas
7.
Rev Med Interne ; 33(9): 503-13, 2012 Sep.
Artículo en Francés | MEDLINE | ID: mdl-22578589

RESUMEN

Neurological and psychiatric manifestations of systemic lupus erythematosus are a heterogeneous set of clinical manifestations grouped under the term of "neuropsychiatric systemic lupus erythematosus". The classification of these manifestations published in 1999 has harmonized the definitions cases used in the studies but did not help the clinician to positively identify a specific manifestation of lupus or a neurological or psychiatric event occurred independently of the disease. Published cases series help us to identify neurological or psychiatric manifestations of lupus but modern diagnosis tools contribution have to be evaluated in order to optimize diagnosis management of such manifestations and to distinguish specific events related to lupus and independent manifestations. In this second part of our literature review about neuropsychiatric lupus, we propose to identify arguments, which could be in favor of lupus responsibility in front of a neurological or psychiatric event, and immunosuppressive treatments which are recommended.


Asunto(s)
Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/terapia , Vasculitis por Lupus del Sistema Nervioso Central/diagnóstico , Vasculitis por Lupus del Sistema Nervioso Central/terapia , Pruebas Neuropsicológicas , Algoritmos , Sistema Nervioso Central/fisiopatología , Técnicas de Diagnóstico Neurológico , Humanos , Incidencia , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/epidemiología , Vasculitis por Lupus del Sistema Nervioso Central/epidemiología , Vasculitis por Lupus del Sistema Nervioso Central/etiología
8.
Rev Med Interne ; 33(9): 491-502, 2012 Sep.
Artículo en Francés | MEDLINE | ID: mdl-22579860

RESUMEN

Systemic lupus erythematosus (SLE) is an autoimmune disease, which primarily affects skin and joints. Peripheral neurologic syndrome and central nervous system (CNS) manifestations are common in lupus patients but are not always attributable to lupus itself. A classification, published in 1999 by the American College of Rheumatology (ACR) research committee, described 12 CNS syndromes and seven peripheral neurologic syndromes compatible with "neuropsychiatric systemic lupus erythematosus" (NPSLE). Despite this consensus, studies which have been published since 1999 have reported a prevalence of NPSLE varying from 20 to 97 %, which shows the diagnosis difficulty and the heterogeneity of neuropsychiatric manifestations in SLE. In order to understand the limits of this classification, we propose in this first part an exhaustive review of publications describing neuropsychiatric manifestations according to the ACR 1999 classification. We also detail case definitions, prevalence and risk factors, clinical characteristics and diagnosis of each lupus-related psychiatric and CNS manifestation.


Asunto(s)
Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/terapia , Vasculitis por Lupus del Sistema Nervioso Central/diagnóstico , Vasculitis por Lupus del Sistema Nervioso Central/terapia , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/epidemiología , Trastornos de Ansiedad/etiología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Diagnóstico Diferencial , Epilepsia/diagnóstico , Epilepsia/epidemiología , Epilepsia/etiología , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/epidemiología , Vasculitis por Lupus del Sistema Nervioso Central/epidemiología , Vasculitis por Lupus del Sistema Nervioso Central/etiología , Pruebas Neuropsicológicas , Prevalencia
9.
Rev Chir Orthop Reparatrice Appar Mot ; 90(5): 475-8, 2004 Sep.
Artículo en Francés | MEDLINE | ID: mdl-15502772

RESUMEN

An inguinal arthrosynovial cyst of the hip joint developed after total hip arthroplasty leading to compression of the femoral vein. This complication occurred after implantation of a non-cemented prosthesis with a ceramic-on-ceramic interface inserted in a polyethylene sandwich. Multiple foreign bodies composed of both ceramic and polyethylene particles were visualized microscopically. Later, rupture of the joint interface required implant replacement. This cyst was a precursor sign of a deteriorating prosthesis surface.


Asunto(s)
Articulación de la Cadera , Prótesis de Cadera/efectos adversos , Quiste Sinovial/etiología , Cerámica , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis
10.
Mol Ecol ; 11(8): 1515-24, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12144670

RESUMEN

Temporal changes at 16 allozyme loci in the Diplodus sargus population of Banyuls-sur-Mer (Mediterranean Sea, France) were monitored. Temporal genetic variation within a single population was examined over two temporal scales: (i) among three year-classes sampled at the same age, and (ii) within a single year-class sampled three times over a two-year period. We observed a significant change in the genotypic structure within the same cohort during the first two years following settlement and before recruitment into the adult population. In addition, comparison of year-classes showed that cohorts differed significantly one year after settlement, whereas they became similar later on before recruitment into the adult population. The observed changes in the genetic structure within and between year-classes may be the result of complex selective processes or genetic drift. Linkage disequilibrium and genetic relatedness data suggest that these changes are due to large variation in reproductive success, followed by homogenization through adult movement. Overall, these results demonstrated a rapid genetic change within a population.


Asunto(s)
Variación Genética , Reproducción/fisiología , Dorada/genética , Animales , Enzimas/análisis , Enzimas/genética , Frecuencia de los Genes , Dorada/fisiología , Estadística como Asunto
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...