Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Int J Biometeorol ; 62(6): 1063-1074, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29516157

RESUMEN

Despite the important roles ground beetles (Coleoptera: Carabidae) play in ecosystems, the highly valued ecosystem services they provide, and ample descriptive documentation of their phenology, the relative impact of various environmental factors on carabid phenology is not well studied. Using the long-term pitfall trap capture data from 12 terrestrial Environmental Change Network (ECN) sites from the UK, we examined how changing climate influenced the phenology of common carabids, and the role particular climate components had on phenological parameters. Of the 28 species included in the analyses, 19 showed earlier start of their activity. This advance was particularly pronounced in the spring, supporting the view that early phenophases have a greater tendency to change and these changes are more directly controlled by temperature than later ones. Autumn activity extended only a few cases, suggesting a photoperiod-driven start of hibernation. No association was found between life-history traits and the ability of species to change their phenology. Air temperatures between April and June were the most important factors determining the start of activity of each species, whilst late season precipitation hastened the cessation of activity. The balance between the advantages and disadvantages of changing phenology on various levels is likely to depend on the species and even on local environmental criteria. The substantially changing phenology of Carabidae may influence their function in ecosystems and the ecosystem services they provide.


Asunto(s)
Cambio Climático , Escarabajos , Estaciones del Año , Animales , Ecosistema , Temperatura , Reino Unido
2.
Fungal Biol ; 118(7): 579-90, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25088072

RESUMEN

Saprolegnia species are destructive pathogens to many aquatic organisms and are found in most parts of the world. Reports based on phylogenetic analysis suggest that Saprolegnia strains isolated from aquatic animals such as crustaceans and frogs are close to Saprolegnia strains isolated from infected fish or fish eggs and vice versa. However, it has often been assumed that host specificity occurs for each individual isolate or strain. Here we demonstrate that Saprolegnia spp. can have multiple hosts and are thus capable of infecting different aquatic organisms. Saprolegnia delica, Saprolegnia hypogyna, and 2 strains of Saprolegnia diclina were isolated from aquatic insects and amphipods while S. delica, Saprolegnia ferax, Pythium pachycaule, and a Pythium sp. were isolated from the water of a medium to fast flowing river. The ITS region of the rRNA gene was sequenced for all isolates. In challenge experiments, all four isolates from insects were found to be highly pathogenic to eggs of Atlantic salmon (Salmo salar) and embryos of the African clawed frog (Xenopus laevis). We found that Saprolegnia spp. isolated from salmon eggs were also able to successfully establish infection in nymphs of stonefly (Perla bipunctata) and embryos of X. laevis). These results suggest that Saprolegnia spp. are capable of infecting multiple hosts, which may give them an advantage during seasonal variation in their natural environments.

3.
Fungal Biol ; 117(11-12): 752-63, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24295914

RESUMEN

Saprolegnia species are destructive pathogens to many aquatic organisms and are found in most parts of the world. Reports based on phylogenetic analysis suggest that Saprolegnia strains isolated from aquatic animals such as crustaceans and frogs are close to Saprolegnia strains isolated from infected fish or fish eggs and vice versa. However, it has often been assumed that host specificity occurs for each individual isolate or strain. Here we demonstrate that Saprolegnia spp. can have multiple hosts and are thus capable of infecting different aquatic organisms. Saprolegnia delica, Saprolegnia hypogyna, and 2 strains of Saprolegnia diclina were isolated from aquatic insects and amphipods while S. delica, Saprolegnia ferax, Pythium pachycaule, and a Pythium sp. were isolated from the water of a medium to fast flowing river. The ITS region of the rRNA gene was sequenced for all isolates. In challenge experiments, all four isolates from insects were found to be highly pathogenic to eggs of Atlantic salmon (Salmo salar) and embryos of the African clawed frog (Xenopus laevis). We found that Saprolegnia spp. isolated from salmon eggs were also able to successfully establish infection in nymphs of stonefly (Perla bipunctata) and embryos of X. laevis). These results suggest that Saprolegnia spp. are capable of infecting multiple hosts, which may give them an advantage during seasonal variation in their natural environments.


Asunto(s)
Anfípodos/microbiología , Especificidad del Huésped , Insectos/microbiología , Ríos/microbiología , Saprolegnia/clasificación , Saprolegnia/fisiología , Animales , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Filogenia , Saprolegnia/genética , Saprolegnia/aislamiento & purificación , Análisis de Secuencia de ADN
4.
Ann Bot ; 112(4): 731-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23798601

RESUMEN

BACKGROUND: Large herbivores are often removed or reduced as part of vegetation restoration programmes, but the resultant increase in vegetation biomass and changes in vegetation structure may favour small mammals. Small mammals may have large impacts on plant community composition via granivory and sapling herbivory, and increased small mammal populations may reduce any benefits of large herbivore removal for highly preferred species. This study tested the impacts of small mammal herbivory, microsite characteristics and their interaction on growth and survival of three montane willow species with differing chemical compositions, Salix lapponum, S. myrsinifolia and S. arbuscula. METHODS: In two separate years, 1-year-old saplings were planted within a 180 ha, large-mammal scrub regeneration exclosure, and either experimentally protected from or exposed to small mammals (bank voles). Saplings were planted in one of two microsite treatments, vegetation mown (to mimic a grazed sward) or disturbed (all above- and below-ground competition removed), and monitored throughout the first year of growth. KEY RESULTS: Approximately 40 % of saplings planted out in each year were damaged by bank voles, but direct mortality due to damage was very low (<2 %). There were no strong species differences in susceptibility to vole damage. Microsite treatment had no impact on the proportion of saplings attacked, but in 2004 saplings in mown microsites were more severely damaged and had smaller increases in size than those in disturbed microsites. In 2003, saplings in mown microsites had smaller increases in stem diameter following attack than those in disturbed microsites. CONCLUSIONS: Planting 1-year-old willow saplings into disturbed microsites may aid growth, reduce the severity of small mammal damage and improve recovery following sub-lethal small mammal damage. Restoration management of montane willow scrub should therefore consider manipulating the planting site to provide disturbed areas of soil.


Asunto(s)
Arvicolinae/fisiología , Herbivoria , Salix/fisiología , Animales
5.
J Environ Qual ; 41(2): 364-72, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22370398

RESUMEN

Buffer strips alongside watercourses are a widely accepted method of reducing nutrient and sediment run-off from agricultural land thereby improving water quality. Little attention, however, has been paid to the ecological status of these areas despite the fact that riparian habitats in good condition can provide multiple benefits. We investigated vegetation patterns and plant-environment relationships within three categories of riparian margins in northeast Scotland. The margins were categorized as unbuffered, buffered, or reference (target), the latter representing the best sites available within the catchments. Vascular plant and soil data were collected from 41 sites along the tributaries of two rivers during 2008 and 2009. Ellenberg indicator values revealed trends of decreasing light availability ( < 0.05) and decreasing pH ( < 0.01) from unbuffered sites to buffered sites to reference sites. Multivariate analysis showed that soil parameters and channel morphology, together with canopy cover and bryophyte abundance, were discriminatory in separating species assemblages. The presence of a tree canopy layer appears to be the key instigator of change in soil conditions and corresponding plant species assemblages. An understanding of the underlying processes is important if vegetation characteristics are to be used effectively as indicators of riparian and water quality and to aid the restoration of riparian habitats.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Desarrollo de la Planta , Plantas/clasificación , Biodiversidad , Escocia , Factores de Tiempo
6.
J Urol ; 174(3): 893-7, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16093982

RESUMEN

PURPOSE: We report the surgical technique and results of epididymal sparing bilateral simple orchiectomy as an esthetic alternative to standard bilateral simple orchiectomy and luteinizing hormone releasing hormone (LH-RH) agonist injection therapy in patients with prostate cancer. MATERIALS AND METHODS: The study included 91 consecutive epididymal sparing bilateral simple orchiectomy (BSO) procedures that were performed at the Atlanta Veterans Affairs Medical Center during a 25-month period. All patients had pathologically confirmed prostate cancer. A total of 52 patients (57.1%) were receiving LH-RH agonist therapy prior to the procedure and the remaining 39 (42.9%) were not. All procedures were performed in an outpatient clinic setting using spermatic cord anesthesia block as the only method of anesthesia. In the 52 patients who were on LH-RH agonist therapy prior to the procedure the overall impression/satisfaction with the procedure was evaluated using a questionnaire. RESULTS: All 91 procedures were performed at the urology outpatient clinic using local anesthesia. Mean patient age was 74.2 years (range 44 to 86). Mean serum prostate specific antigen was 58.9 ng/ml. The mean time required to perform the spermatic cord anesthesia block was 3.9 minutes (range 2 to 6) and the volume of anesthetic solution was 18.9 ml per case (range 10 to 32). Despite significant difference in testicular size between patients receiving and not receiving LH/RH agonists there were no differences in anesthesia time or anesthetic volume (3.9 and 3.9 minutes, p = 0.97, and 18.6 and 19.4 ml, respectively, p = 0.47). Mean operative time for BSO excluding anesthesia time was 36.9 minutes (range 18 to 70). Mean operative time was similar in patients receiving and not receiving LH-RH agonists (36.2 and 37.8 minutes, respectively, p = 0.39). The procedure was well tolerated, as judged by the mean intraoperative pain score during BSO of 0.2 (range 0 to 3). The majority of patients (76 or 83.5%) were pain-free during the procedure. Pain scores were similar in patients who were and were not receiving LH-RH agonists during BSO (p = 0.97). There were no adverse events. Followup data were available on 26 of the 52 patients who were receiving LH-RH agonist therapy prior to the procedure. Of them 96.2% were satisfied with the results and 84.6% preferred the procedure over medical castration therapy with LH-RH agonist therapy. CONCLUSIONS: Epididymal sparing bilateral simple orchiectomy is a simple and safe procedure that can be conveniently performed in an outpatient clinic setting using pure local anesthesia. Preservation of the epididymis and subsequent epididymoplasty is effective for maintaining the esthetic appearance of the scrotum and patient satisfaction. The procedure offers patients the convenience of 1-time surgical therapy over lifelong medical injection therapy at a significantly lower cost and without significantly compromising the esthetic appearance of the scrotum.


Asunto(s)
Imagen Corporal , Epidídimo/cirugía , Estética , Hormona Liberadora de Gonadotropina/agonistas , Terapia Neoadyuvante , Orquiectomía/métodos , Neoplasias de la Próstata/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Ambulatorios , Anestesia Local , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Bloqueo Nervioso , Orquiectomía/psicología , Satisfacción del Paciente , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/tratamiento farmacológico , Cordón Espermático/inervación , Encuestas y Cuestionarios , Técnicas de Sutura
7.
J Urol ; 172(6 Pt 1): 2358-61, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15538267

RESUMEN

PURPOSE: We evaluated the safety and effectiveness of spermatic cord anesthetic block (SCAB) as the only method of anesthesia for bilateral simple orchiectomy in an outpatient clinic setting. MATERIALS AND METHODS: The study included 141 consecutive bilateral simple orchiectomy (BSO) procedures performed at Atlanta Veterans Affairs Medical Center during a 33-month period. All procedures were performed in an outpatient clinic setting using SCAB as the only method of anesthesia. The anesthetic solution consisted of an equal mixture of 1% lidocaine with epinephrine at 1:100,000 and 0.25% bupivacaine. A 10-point visual analog pain scale was used to assess pain/discomfort at baseline, during SCAB instillation and during BSO. Postoperatively overall patient impression/satisfaction with SCAB as a method of anesthesia was determined. RESULTS: Nine of the 141 available cases (6.4%) were excluded from study. The remaining 132 cases were included in data analysis. Mean patient age was 75.4 years (range 44 to 86). A total of 76 patients (57.6%) were receiving luteinizing hormone releasing hormone agonist therapy at the time of the procedure. The mean time needed to perform SCAB and BSO was 3.9 (range 2 to 6) and 33.0 minutes (range 12 to 70), respectively. The average volume of anesthetic solution was 20.1 ml per case (range 10 to 32). The mean pain score was 0.36 (range 0 to 8), 1.96 (range 0 to 8) and 0.33 (range 0 to 5) at baseline, and during SCAB and BSO, respectively. Of the patients 102 (77.3%) underwent a painless procedure (pain score = 0), 29 (21.9%) experienced transient pain that was mild in nature (pain score 4 or less) and only 1 (0.7%) had a pain score of 5. Pain scores were similar in patients who were and were not receiving luteinizing hormone releasing hormone agonists at baseline (p = 0.36), during SCAB instillation (p = 0.89) and during BSO (p = 0.36). The overall impression/satisfaction with SCAB as a method of anesthesia was rated as highly satisfactory by 91.7% of patients and satisfactory by 8.3%. There were no intraoperative adverse events related to SCAB. CONCLUSIONS: SCAB is a simple, safe and highly effective method of anesthesia for scrotal procedures. It allows such procedures to be performed in an outpatient clinic setting, offering convenience and the potential for cost savings.


Asunto(s)
Anestesia Local , Orquiectomía , Escroto/cirugía , Cordón Espermático , Adulto , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Ambulatorios , Humanos , Masculino , Persona de Mediana Edad
8.
Urology ; 64(2): 298-301, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15302482

RESUMEN

OBJECTIVES: To evaluate the risk of hyponatremia and transurethral resection of the prostate (TURP) syndrome after bipolar saline TURP in patients with large-volume, benign prostatic hyperplasia and statistically significant comorbidities. METHODS: Five patients with large symptomatic benign prostatic hyperplasia and significant comorbidities underwent saline TURP. Data were collected regarding patient profile, prostate weight, operative time, and perioperative events. In particular, we studied and compared the preoperative and postoperative serum sodium concentrations and hematocrit. RESULTS: The mean age was 68 years (range 57 to 76). The mean resection weight of the prostatic chips was 49.6 g (range 37 to 62). Senior urology residents under the supervision of the university faculty performed all procedures. The average operative time was 2 hours, 22 minutes (range 98 to 175 minutes). The mean serum sodium concentration decreased by 1.6 mg/dL (from 138.4 mg/dL preoperatively to 136.8 mg/dL postoperatively). The mean hematocrit decreased by 5.60% (from 40.24% preoperatively to 34.64% postoperatively). Postoperative recovery was uneventful in all 5 patients. CONCLUSIONS: Bipolar saline TURP is safe and eliminates the risk of TURP syndrome in high-risk patients with large prostates that require lengthy resection. In addition, the system permits the faculty to spend the time needed for teaching and training urology residents without compromising patient safety.


Asunto(s)
Endoscopios , Hiponatremia/inducido químicamente , Complicaciones Posoperatorias/inducido químicamente , Hiperplasia Prostática/cirugía , Cloruro de Sodio/efectos adversos , Resección Transuretral de la Próstata , Absorción , Anciano , Diseño de Equipo , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Próstata/patología , Hiperplasia Prostática/sangre , Riesgo , Cloruro de Sodio/administración & dosificación , Cloruro de Sodio/farmacocinética , Síndrome , Irrigación Terapéutica/efectos adversos , Irrigación Terapéutica/instrumentación , Resección Transuretral de la Próstata/instrumentación
9.
J Urol ; 172(3): 1042-4, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15311033

RESUMEN

PURPOSE: Cosmetic expectation has a major role in influencing patient choice between medical and surgical castration, and yet to our knowledge the fate of the medically castrated testis has never been accurately tested and documented in the literature. We determined the weight of testes in patients receiving medical castration and compared it to that in a control group receiving primary surgical castration. MATERIALS AND METHODS: We performed a retrospective analysis of 88 patients with prostate cancer who underwent bilateral simple orchiectomy with epididymal sparing. The study was done at Veterans Administration Medical Center, Atlanta, Georgia. All procedures were performed using local anesthesia in an outpatient clinical setting. Patients were divided into 2 groups, namely 52 receiving luteinizing hormone releasing hormone (LH-RH) agonist therapy prior to the procedure and 36 controls who were not. The weight of the testes was compared between the 2 groups. RESULTS: Median testicular weight significantly decreased following treatment with LH-RH agonist compared to the control group. Median weight of the testis was 7.0 gm (range 0.5 to 22.0) in the LH-RH agonist group compared to 15 gm (range 4.0 to 44.0) in the control group (p = 0.0049 x 10). CONCLUSIONS: Medical castration with LH-RH agonist therapy significantly decreases the weight of testes and compromises the cosmetic outcome. Since cosmetic expectation has a major role in influencing patient choice between medical and surgical castration, patients should be fully informed about the significant testicular atrophy associated with medical castration before making their decision.


Asunto(s)
Antagonistas de Andrógenos/uso terapéutico , Antineoplásicos Hormonales/uso terapéutico , Hormona Liberadora de Gonadotropina/agonistas , Neoplasias de la Próstata/tratamiento farmacológico , Testículo/efectos de los fármacos , Atrofia , Humanos , Masculino , Persona de Mediana Edad , Orquiectomía , Tamaño de los Órganos/efectos de los fármacos , Neoplasias de la Próstata/cirugía , Testículo/patología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA