It is usually believed that Darwin’s theory leads to a smooth gradual evolution, so that mass extinctions must be caused by external shocks. However, it has recently been argued that mass extinctions arise from the intrinsic dynamics of Darwinian evolution. Species become extinct when swept by intermittent avalanches propagating through the global ecology. These ideas are made concrete through ...

Corals perform simultaneous mass spawning around the full moon. Most Acropora species release gamete bundles, which are a complex of eggs and sperm, into the seawater. Then, gamete bundles are separated into eggs and sperm. Eggs are fertilized when sperm and eggs come in contact with each other. However, it is still unclear how sperm meet the eggs of the same species in the presence of many egg...

Gastrointestinal motility and plasma PYY levels were investigated under chronic progressive large bowel obstruction in dogs. The obstruction device was applied around the descending colon at a laparotomy and gastrointestinal motility was recorded with strain gauge force transducers in the conscious state. Complete obstruction occurred at 26 days (21-33 days). The duration of postprandial interr...

antioxidant properties of ghrelin have been demonstrated in recent studies. in the present study, theeffects of chronic administration of ghrelin on the motility and plasma membrane integrity of rat spermatozoa during incubation at 37ºc were investigated. thirty 45-day-old male wistar rats were divided into control and treatment groups. rats in the treatment group were daily injected subcutaneo...

OBJECTIVES To determine semen quality and reproductive hormone levels in young Faroese men. DESIGN Descriptive cross-sectional study of Faroese men compared with Danish men. SETTING Faroese one-centre study. PARTICIPANTS 481 men born from 1981 to 1987 and investigated from 2007 to 2010. OUTCOME MEASURES Sperm concentration, semen volume, total sperm count, sperm motility, sperm morpholo...

Objective To evaluate the relationship between preoperative grade and postoperative changes of semen parameters following left inguinal varicocelectomy. Methods This study included 44 patients undergoing left microsurgical inguinal varicocelectomy. Internal spermatic veins were classified as large (4 mm or more in diameter), medium (2-4 mm), or small (2 mm or less). Changes in sperm activity,...

Objective: To evaluate the restoration of sperm motility with antioxidant oils (Virgin coconut oil and Corn oil) therapy in Phenytoin induced testicular toxicity rats. Study Design: Experimental Study. Setting: Al-Tibri Medical College Hospital. Period: November 2019 to March 2020. Material & Methods: Forty-eight male albino rats weighing between 150-250gms were taken from animal house medi...

background: oxidative stress is detrimental to semen quality and has a significant role in the etiology of male subfertility. methods: dietary intake of antioxidants were compared between thirty two men with oligolastheno/ teratazoospermic (cases) and 32 normospermic volunteers (controls) attending fertility clinic in mirza koochak-khan hospital in tehran, iran. all participants were nonsmokers...

Objective(s): Failed fertilization after intra-cytoplasmic sperm injection (ICSI) is mainly attributed to failed oocyte activation and can be overcome by artificial oocyte activation (AOA). The present study aims to compare in vitro outcomes of ICSI following two different assisted oocyte activation chemical procedures (SrCl2 and Ionomycin) in sibling oocytes of ICSI candidates.Materials and Me...

This study was designed to compare the effect of straw size (0.25 vs. 0.5 ml) and thawing time (30 vs. 60 sec) on the quality of cryopreserved buffalo bull semen. Sperm motility, plasma membrane integrity and viability were higher (p ≤ 0.05) in 0.25 ml than 0.5 ml straw, thawed at 37°C either for 30 or 60 sec. In conclusion, cryopreservation of buffalo semen in 0.25 ml straw resulted in a highe...