28 research outputs found

    Dealing with Food and Eggs in Mouthbrooding Cichlids: Structural and Functional Trade-Offs in Fitness Related Traits

    Get PDF
    As in any vertebrate, heads of fishes are densely packed with functions. These functions often impose conflicting mechanical demands resulting in trade-offs in the species-specific phenotype. When phenotypical traits are linked to gender-specific parental behavior, we expect sexual differences in these trade-offs. This study aims to use mouthbrooding cichlids as an example to test hypotheses on evolutionary trade-offs between intricately linked traits that affect different aspects of fitness. We focused on the oral apparatus, which is not only equipped with features used to feed and breathe, but is also used for the incubation of eggs. We used this approach to study mouthbrooding as part of an integrated functional system with diverging performance requirements and to explore gender-specific selective environments within a species.Because cichlids are morphologically very diverse, we hypothesize that the implications of the added constraint of mouthbrooding will primarily depend on the dominant mode of feeding of the studied species. To test this, we compared the trade-off for two maternal mouthbrooding cichlid species: a "suction feeder" (Haplochromis piceatus) and a "biter" (H. fischeri). The comparison of morphology and performance of both species revealed clear interspecific and intersex differences. Our observation that females have larger heads was interpreted as a possible consequence of the fact that in both the studied species mouthbrooding is done by females only. As hypothesized, the observed sexual dimorphism in head shape is inferred as being suboptimal for some aspects of the feeding performance in each of the studied species. Our comparison also demonstrated that the suction feeding species had smaller egg clutches and more elongated eggs.Our findings support the hypothesis that there is a trade-off between mouthbrooding and feeding performance in the two studied haplochromine cichlids, stressing the importance of including species-specific information at the gender level when addressing interspecific functional/morphological differences

    Exercise therapy in Type 2 diabetes

    Get PDF
    Structured exercise is considered an important cornerstone to achieve good glycemic control and improve cardiovascular risk profile in Type 2 diabetes. Current clinical guidelines acknowledge the therapeutic strength of exercise intervention. This paper reviews the wide pathophysiological problems associated with Type 2 diabetes and discusses the benefits of exercise therapy on phenotype characteristics, glycemic control and cardiovascular risk profile in Type 2 diabetes patients. Based on the currently available literature, it is concluded that Type 2 diabetes patients should be stimulated to participate in specifically designed exercise intervention programs. More attention should be paid to cardiovascular and musculoskeletal deconditioning as well as motivational factors to improve long-term treatment adherence and clinical efficacy. More clinical research is warranted to establish the efficacy of exercise intervention in a more differentiated approach for Type 2 diabetes subpopulations within different stages of the disease and various levels of co-morbidity

    A randomized placebo-controlled trial on the effectiveness of an herbal formula to alleviate menopausal vasomotor symptoms

    Full text link
    Objective: To evaluate the effectiveness of a formula containing Chinese herbs and Cimicifuga racemosa in alleviating vasomotor symptoms and improving quality of life. Methods: Between September 2004 and October 2005, 93 healthy women aged 45 to 65 years who reported six or more vasomotor symptoms per 24 hours were recruited into a 20-week randomized, double-blind, placebo-controlled trial. Women were consulted in clinics conducted within the Sydney metropolitan area. After a 4-week baseline period, women were randomly allocated to receive herbal (equivalent to 3,150 mg dry herb) or identical placebo tablets for 16 weeks. Women recorded the number and severity (1 = mild to 4 = very severe) of vasomotor symptoms in a daily hot flash diary and completed the Greene Climacteric and Hot Flash Related Daily Interference scales at each monthly consultation. Results: Intention-to-treat and per-protocol analyses found no statistically significant differences in mean hot flash scores (product of frequency and intensity), Greene Climacteric Scale scores, and Hot Flash Related Daily Interference Scale scores between the placebo and herbal treatment groups after 16 weeks of intervention. Conclusions: This herbal formula containing Chinese herbs and Cimicifuga cannot be recommended to alleviate menopausal vasomotor symptoms or improve quality of life. © 2009 by The North American Menopause Society

    Fish consumption and risk of stroke, coronary heart disease, and cardiovascular mortality in a Dutch population with low fish intake

    No full text
    Background/objectives: Fish consumption of at least 1 portion/week is related to lower cardiovascular disease (CVD) risk. It is uncertain whether a less frequent intake is also beneficial and whether the type of fish matters. We investigated associations of very low intakes of total, fatty, and lean fish, compared with no fish intake, with 18-year incidences of stroke, coronary heart disease (CHD), and CVD mortality. Methods: Data were used from 34,033 participants, aged 20–70 years, of the EPIC-Netherlands cohort. Baseline (1993–1997) fish consumption was estimated using a food frequency questionnaire. We compared any fish consumption, <1 portion/week (<100 g) and ≥1 portion/week to non-fish consumption. Results: During 18 follow-up years, 753 stroke events, 2134 CHD events, and 540 CVD deaths occurred. Among the fish consumers (~92%) median intakes of total, lean, and fatty fish were 57.9, 32.9, and 10.7 g/week, respectively. Any fish consumption compared with non-consumption was not associated with incidences of stroke, CHD, MI, and CVD mortality. Furthermore, consumption of <1 portion/week of total, fatty, or lean fish was not associated with any CVD outcome, as compared with non-consumption. Consumption of ≥1 portion/week of lean fish (HR: 0.70, 95% CI: 0.57–0.86) and of fatty fish (HR: 0.63, 95% CI: 0.39–1.02) were associated with lower incidence of ischaemic stroke. Conclusions: Baseline fish consumption of <1 portion/week, regardless of the type of fish, was unrelated to incidences of stroke, CHD, and CVD mortality in this Dutch cohort. Consumption of ≥1 portion/week of fatty or of lean fish reduced the incidence of ischaemic stroke
    corecore