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3.
Am J Bot ; 94(11): 1853-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21636380

RESUMO

Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reported on inbreeding depression in moss species. Here, we present data on the magnitude of inbreeding depression in sporophytic traits of moss species with contrasting breeding systems. In Ceratodon purpureus (Ditrichaceae), a moss species with separate sexes, self-fertilizations between sibling gametophytes (intergametophytic selfing) significantly reduced fitness in two of four traits quantified, with seta length and capsule length having inbreeding coefficients significantly different from zero, resulting in a cumulative inbreeding depression that was also significantly greater than zero (δ = 0.619 ± 0.076). In hermaphroditic Funaria hygrometrica (Funariaceae), there was no evidence of inbreeding depression in seta length, spore number, capsule mass, or capsule length resulting from sporophytes generated by self-fertilization within an individual (intragametophytic selfing), and cumulative inbreeding depression was also not different from zero (δ = 0.038 ± 0.022). These results provide evidence that, despite haploid dominance, inbreeding depression can be expressed at the diploid stage in mosses and may have implications for the evolution and maintenance of combined versus separate sexes in mosses.

5.
Hum Reprod ; 20(9): 2542-5, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15919775

RESUMO

BACKGROUND: The study was carried out to determine the most likely time of day for the onset of the LH surge as detected using urine LH dipsticks, and to calculate the optimum time interval from the onset of the LH surge to intrauterine insemination (IUI). METHODS: A prospective study of 1540 cycles of IUI with donor sperm at Cleveland Fertility Centre, Middlesbrough, between June 1990 and February 2004. Only 951 cycles (where a positive urine LH dipstick result was immediately preceded by a negative result) were included in our study. To determine the best time interval between the onset of the LH surge and IUI, women were divided into five subgroups according to the positive urine test-IUI time interval and the pregnancy rate and live birth rate per cycle were calculated for each group. RESULTS: The first positive test was most frequently (44.5%) found at lunch-time (11:00-15:00). The live birth per cycle achieved was 5.6% when the insemination was performed 18-23 h from the first detection of the LH surge, and 11.7% when it was performed between 24 and 42 h. The live birth rate declined to 6.5% when IUI was performed later than that. Overall, no significant differences were discovered in live birth or pregnancy rate when insemination was performed at any of the time points between 18 and 53 h. CONCLUSION: Our study suggested that lunch-time is the best time to check for the LH surge using urine dipsticks and insemination at any time between 18 and 53 h after the onset of the surge will produce optimal results.


Assuntos
Ritmo Circadiano , Inseminação Artificial/métodos , Hormônio Luteinizante/urina , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Kit de Reagentes para Diagnóstico , Fitas Reagentes , Espermatozoides
6.
Gastroenterology ; 122(5): 1235-41, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11984509

RESUMO

BACKGROUND & AIMS: Patient surveys suggest that fatigue is a common problem in primary biliary cirrhosis (PBC). The actual extent of the problems caused by fatigue in PBC has yet to be determined as previous studies addressing this question have tended to use selected patient subgroups and subjective or non-quantitative fatigue assessment tools. Here, we have attempted to more accurately assess the extent of fatigue in PBC, and the specificity of the symptom for this disease, by the application of an objective measure of fatigue impact (the fatigue impact score [FIS]) to a geographically based patient cohort, age- and sex-matched normal controls, and chronic liver disease controls. METHODS: Postal completion of the FIS and linked symptom assessment tools. RESULTS: Median FIS was significantly higher in patients (n = 136) than community controls (40 [0-138] vs. 28 [0-156]; P < 0.0001) and chronic liver disease controls (n = 38) (20.5 [0-145]; P < 0.05). Fatigue scores in the 11 patients who had undergone liver transplantation (median 3.5 years previously) were the same as those in non-transplanted patients with advanced disease. CONCLUSIONS: Fatigue is a significant and specific problem in PBC. It is not, however, universal and affects fewer patients than has previously been thought to be the case based on data from selected patient cohorts. This definition of the "normal range" for fatigue in PBC will assist in future studies of etiology and therapy.


Assuntos
Fadiga/etiologia , Cirrose Hepática Biliar/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Humanos , Hepatopatias/complicações , Transplante de Fígado , Masculino , Pessoa de Meia-Idade
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