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Reproductive Capabilities (reproductive + capability)

Distribution by Scientific Domains
Medical Sciences60%
Life Sciences40%

Selected Abstracts

Is competition important to arctic zooplankton community structure?

FRESHWATER BIOLOGY, Issue 9 2004
Andrew R. Dzialowski
Summary 1. Daphnia pulex and Daphnia middendorffiana are commonly found in the Toolik Lake region of arctic Alaska. These two species are very similar morphologically, although their natural distributions differ markedly: D. pulex is restricted to shallow ponds, while D. middendorffiana is widely distributed and found in a variety of ponds and lakes. We compared the reproductive capabilities of D. pulex and D. middendorffiana grown under similar resource conditions and in the absence of the invertebrate predator Heterocope septentrionalis. In situ life table and mesocosm experiments were conducted in Toolik Lake and Dam Pond, habitats that have historically contained natural populations of D. middendorffiana, but never D. pulex. 2. Daphnia pulex exhibited a significantly higher net growth rate than D. middendorffiana in both life table and mesocosm experiments although D. pulex has never been found in either Toolik Lake or Dam Pond. Daphnia middendorffiana exhibited a negative net growth rate in Dam Pond, which had lower resource levels then Toolik Lake. Therefore, the smaller D. pulex appears to have a lower food threshold concentration than the larger D. middendorffiana. 3. Our results indicate that D. pulex is a superior resource competitor in the Toolik Lake region. These results combined with distributional patterns suggest that the restricted distribution of D. pulex in these arctic lakes and ponds cannot be explained by resource competition alone. We suggest that in the presence of H. septentrionalis, predation is an important factor structuring arctic zooplankton communities in the Toolik Lake region. [source]

Inhibition of myostatin with emphasis on follistatin as a therapy for muscle disease

MUSCLE AND NERVE, Issue 3 2009
Louise R. Rodino-Klapac PhD
Abstract In most cases, pharmacologic strategies to treat genetic muscle disorders and certain acquired disorders, such as sporadic inclusion body myositis, have produced modest clinical benefits. In these conditions, inhibition of the myostatin pathway represents an alternative strategy to improve functional outcomes. Preclinical data that support this approach clearly demonstrate the potential for blocking the myostatin pathway. Follistatin has emerged as a powerful antagonist of myostatin that can increase muscle mass and strength. Follistatin was first isolated from the ovary and is known to suppress follicle-stimulating hormone. This raises concerns for potential adverse effects on the hypothalamic,pituitary,gonadal axis and possible reproductive capabilities. In this review we demonstrate a strategy to bypass off-target effects using an alternatively spliced cDNA of follistatin (FS344) delivered by adeno-associated virus (AAV) to muscle. The transgene product is a peptide of 315 amino acids that is secreted from the muscle and circulates in the serum, thus avoiding cell-surface binding sites. Using this approach our translational studies show increased muscle size and strength in species ranging from mice to monkeys. Adverse effects are avoided, and no organ system pathology or change in reproductive capabilities has been seen. These findings provide the impetus to move toward gene therapy clinical trials with delivery of AAV-FS344 to increase size and function of muscle in patients with neuromuscular disease. Muscle Nerve 39: 283,296, 2009 [source]

Women with obstetric fistula in Ethiopia: a 6-month follow up after surgical treatment

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2008
A Browning
Objective, To quantify surgical and quality of life outcomes 6 months after obstetric fistula repair. Design, A prospective study. Women were examined and questioned at discharge and at follow-up appointment. Setting, The Barhirdar Hamlin Fistula Centre, a dedicated unit treating women with obstetric fistula in northern Ethiopia. Population, All women admitted to the Barhirdar Hamlin Fistula Centre suffering from vesicovaginal (WF) and rectovaginal fistulae (RVF). Methods, All women were asked to return for a follow-up appointment 6 months after surgical treatment. A standardised questionnaire and examination were used and information entered into a database. Main outcomes measures, Urinary and anal continence status; extent of return to previous family situation, employment, social activities and reproductive capabilities. Results, Continence status at discharge was largely maintained at 6 months and quality of life was improved. Many of those incontinent on discharge improved; a small number apparently cured at discharge had later recurrence of incontinence. Conclusions, Surgical treatment for obstetric fistula is successful in maintaining continence and improving quality of life of women at 6-months follow up. [source]

Life table and heat tolerance of Acyrthosiphon pisum (Hemiptera: Aphididae) in subtropical Taiwan

ENTOMOLOGICAL SCIENCE, Issue 3 2008
Wei-Nung LU
Abstract The effect of temperature on the life table of Acyrthosiphon pisum reared on Pisum sativum was evaluated under laboratory conditions using temperatures of 10, 15, 20, 25, 30, and 35°C. The development time of juvenile A. pisum decreased with increasing temperature (from 21.3 days at 10°C to 4.7 days at 35°C). Adult longevity also decreased with increasing temperature (from 53.2 days at 10°C to 2.3 days at 35°C). Interestingly, 70% and 25% of A. pisum nymphs reared at 30°C and 35°C, respectively, successfully developed into adults. These temperatures have previously been considered unsuitable for A. pisum development. However, adult aphids reared at 30°C and 35°C failed to reproduce. Linear regression analysis revealed that the lower development threshold of A. pisum was 153.1 degree-days above 1.9°C. Maximal average reproductive capability was observed at 10°C for A. pisum adults, with each adult producing more than 120 nymphs. The intrinsic rate of increase (rm) of A. pisum increased from 0.124/day at 10°C to 0.337/day at 25°C, whereas opposite trends were observed for the net reproductive rate (R0) and the mean generation time (GT). At 20°C and 25°C, the intrinsic rate of increase of A. pisum was significantly higher than at 10°C and 15°C (P < 0.0001), indicating that 20°C and 25°C are within the optimal range for the growth of A. pisum, and that 30°C is beyond the upper threshold limit for reproduction, which involves a temperature range that is narrower than that of the survival range (upper limit is unknown, but above 35°C). [source]