RESUMEN
Restricted seed dispersal frequently leads to fine-scale spatial genetic structure (i.e., FSGS) within plant populations. Depending on its spatial extent and the mobility of pollinators, this inflated kinship at the immediate neighbourhood can critically impoverish pollen quality. Despite the common occurrence of positive FSGS within plant populations, our knowledge regarding the role of long-distance pollination preventing reproductive failure is still limited. Using microsatellite markers, we examined the existence of positive FSGS in two low-density populations of the tree Pyrus bourgaeana. We also designed controlled crosses among trees differing in their kinship to investigate the effects of increased local kinship on plant reproduction. We used six pollination treatments and fully monitored fruit production, fruit and seed weight, proportion of mature seeds per fruit, and seed germination. Our results revealed positive FSGS in both study populations and lower fruit initiation in flowers pollinated with pollen from highly-genetically related individuals within the neighbourhood, with this trend intensifying as the fruit development progressed. Besides, open-pollinated flowers exhibited lower performance compared to those pollinated by distant pollen donors, suggesting intense qualitative pollen limitation in natural populations. We found positive fine-scale spatial genetic structure is translated into impoverished pollen quality from nearby pollen donors which negatively impacts the reproductive success of trees in low-density populations. Under this scenario of intrapopulation genetic rescue by distant pollen donors, the relevance of highly-mobile pollinators for connecting spatially and genetically distant patches of trees may be crucial to safeguarding population recruitment.
Asunto(s)
Estructuras Genéticas , Genética de Población , Repeticiones de Microsatélite/genética , Pyrus/genética , Flores/genética , Flores/fisiología , Frutas/genética , Frutas/fisiología , Depresión Endogámica , Polen/genética , Polen/fisiología , Polinización , Pyrus/fisiología , Reproducción , Dispersión de Semillas , Semillas/genética , Semillas/fisiología , Análisis Espacial , ÁrbolesRESUMEN
Fruit-frugivore interactions are critical for the dynamics and evolution of many plant communities. The strength of the interactions between a given plant species and different frugivore guilds (e.g., seed dispersers, seed predators) often vary in space due to changes in plant extrinsic factors (e.g., frugivore abundances) and plant traits (e.g., fruit size and reward). By reciprocally translocating Pyrus bourgaeana ripe fruits representative of five Mediterranean localities during 2 consecutive years, we experimentally quantified guild-specific variations among populations in frugivory strength, while accounted for plant-intrinsic and- extrinsic factors. Though overall fruit removal did not differ among localities, there were strong guild-specific differences in fruit removal strength. Fruit removal by pulp feeders, seed dispersers, and fruit predators varied among populations up to 8.5-, 5.6-, and 4.0-folds, respectively. These strong variations seemed mediated by changes in frugivore relative abundances rather than on availability of alternative fruits. As expected, all fruit traits considered (e.g., fruit size, pulp amount) markedly varied among tree populations. However, no frugivore guild showed preference for fruits from any locality, suggesting that fruit traits did not contribute much to differences in frugivory strength among populations. Since the functional diverse frugivore guilds played contrasting roles in P. bourgaeana dynamics (e.g., seed dispersal vs. seed predation), our study highlights the importance of accounting for functional diversity in frugivore guilds when estimating spatial variations in the strenght of seed dispersal. This investigation also illustrates a neglected but widely applicable experimental approach to identify the relative importance of extrinsic factors and fruit traits in mediating fruit-frugivore interactions.
Asunto(s)
Dispersión de Semillas , Conducta Alimentaria , Frutas , Herbivoria , Semillas , ÁrbolesRESUMEN
INTRODUCTION: Cinacalcet has proved effective to control secondary hyperparathyroidism in patients on haemodialysis (HD). Some studies have reported an appropriate secondary hyperparathyroidism control and a better compliance after intradialytic use of calcimimetics. OBJECTIVES: To assess the effect of post-dialysis calcimimetics use on mineral bone disorders and calcimimetics gastrointestinal tolerability in our HD unit. MATERIAL AND METHODS: A 12-week single-centre prospective study in HD patients treated with cinacalcet (>2 months). Two study periods: Usual outpatient use (Stage 1) and use after HD session (Stage 2). ENDPOINTS: 1) Biochemical MBD data; 2) Gastrointestinal Symptom Rating Scale (GSRS) for gastrointestinal tolerability, and visual analogic scale (VAS) for satisfaction; 3) Adherence: Morisky-Green test (MG) and final tablet count (TC). RESULTS: Sixty-two HD patients. Fourteen received cinacalcet (22.5%). TEN patients were included, mean age was 60.9 years; patients had received HD for 80.9 months. Mean Charlson index: 9. Biochemical data: Stage 1 (initial vs. final): Ca 8.8 ± 0.5 vs. 9.1 ± 0.7 mg/dl (p<0.05); P 5.2 ± 0.8 vs. 4.5 ± 1.6 mg/dl, iPTH 360.3 ± 232.7 vs. 349 ± 122 pg/ml. MG: 70%. Stage 2 (initial vs. final): Ca 9.1 ± 0.7 vs. 8.8 ± 0.6 mg/dl; P 4.5 ± 1.6 vs. 4.6 ± 1.3 mg/dl, iPTH 360.3 ± 232.7 vs. 349 ± 122 pg/ml. TC: 89%. GSRS and VAS were better in Stage 2 (GSRS 7.5 ± 5.2 vs. 4.3 ± 1.9; VAS 4.8 ± 2.3 vs. 6.9 ± 2.8). No significant changes were observed in calcimimetic dose (201 vs. 207 mg/wk), number of phosphate binders (9 vs. 8.2 pts/day), native vitamin D (70 vs. 60%), selective vit D receptor activators (30%), or suitable dialysis parameters. CONCLUSIONS: Post-dialysis use of calcimimetic was effective in secondary hyperparathyroidism control, improved gastrointestinal tolerability and ameliorated patients' satisfaction. Based on our findings, post-dialysis use of calcimimetics should be considered in selected patients with low therapeutic compliance.
Asunto(s)
Calcimiméticos/administración & dosificación , Cinacalcet/administración & dosificación , Enfermedades Gastrointestinales/inducido químicamente , Hiperparatiroidismo Secundario/tratamiento farmacológico , Diálisis Renal , Anciano , Atención Ambulatoria , Calcimiméticos/efectos adversos , Calcio/sangre , Cinacalcet/efectos adversos , Esquema de Medicación , Femenino , Enfermedades Gastrointestinales/prevención & control , Humanos , Hiperparatiroidismo Secundario/sangre , Hiperparatiroidismo Secundario/etiología , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Hormona Paratiroidea/sangre , Satisfacción del Paciente , Fósforo/sangre , Estudios Prospectivos , Diálisis Renal/efectos adversos , Equivalencia Terapéutica , Escala Visual AnalógicaRESUMEN
Stomatococcus mucilaginosus is a gram-positive coccus present in the normal flora of the mouth and upper respiratory tract of humans. Although traditionally believed to be an organism of low virulence, S. mucilaginosus has recently been recognized as an emerging opportunistic pathogen, especially in patients with chronic immunosuppressive diseases. This report describes the case of a patient with known mitral valve prolapse, who presented with a mycotic cerebral aneurysm revealing a non-nosocomial spontaneous S. mucilaginosus endocarditis. The spectrum of infections due to this opportunistic pathogen is reviewed, with particular focus on assessing the clinical characteristics and prognosis of S. mucilaginosus infective endocarditis.