نتایج جستجو برای: gradient selected sperm

تعداد نتایج: 533627  

Journal: :Computers in biology and medicine 2008
Enrique Alegre Michael Biehl Nicolai Petkov Lidia Sánchez

We consider images of boar spermatozoa obtained with an optical phase-contrast microscope. Our goal is to automatically classify single sperm cells as acrosome-intact (class 1) or acrosome-damaged (class 2). Such classification is important for the estimation of the fertilization potential of a sperm sample for artificial insemination. We segment the sperm heads and compute a feature vector for...

Journal: :Reproductive biomedicine online 2006
Tamer M Said Ashok Agarwal Sonja Grunewald Manja Rasch Hans-Juergen Glander Uwe Paasch

Magnetic-activated cell sorting (MACS) using paramagnetic annexin V-conjugated microbeads eliminates spermatozoa with externalized phosphatidylserine, which is considered one of the features of apoptosis. The objective of this study was to evaluate sperm recovery following the use of MACS as a sperm preparation technique. Mature spermatozoa were separated and divided into two fractions: the fir...

Journal: :Asian journal of andrology 2012
Cendrine Geoffroy-Siraudin Anderson Dieudonné Loundou Fanny Romain Vincent Achard Blandine Courbière Marie-Hélène Perrard Philippe Durand Marie-Roberte Guichaoua

Semen from 10 932 male partners of infertile couples was analysed and sperm parameter trends were evaluated at the Reproduction Biology Laboratory of the University Hospital of Marseille (France) between 1988 and 2007. After 3-6 days of abstinence, semen samples were collected. Measurements of seminal fluid volume, pH, sperm concentration, total sperm count, motility and detailed morphology of ...

Journal: :Archives of Environmental Contamination and Toxicology 2008

Journal: :The EMBO journal 2005
Martin Böhmer Qui Van Ingo Weyand Volker Hagen Michael Beyermann Midori Matsumoto Motonori Hoshi Eilo Hildebrand Ulrich Benjamin Kaupp

The events that occur during chemotaxis of sperm are only partly known. As an essential step toward determining the underlying mechanism, we have recorded Ca2+ dynamics in swimming sperm of marine invertebrates. Stimulation of the sea urchin Arbacia punctulata by the chemoattractant or by intracellular cGMP evokes Ca2+ spikes in the flagellum. A Ca2+ spike elicits a turn in the trajectory follo...

Journal: :international journal of fertility and sterility 0
mohammad hossein nasr esfahani mohammad reza deemeh marziyeh tavalaee mohammad hadi sekhavati hamid gourabi

objective: selection of sperm for intra-cytoplasmic sperm injection (icsi) is usually considered as the ultimate technique to alleviate male-factor infertility. in routine icsi, selection is based on morphology and viability which does not necessarily preclude the chance injection of dna-damaged or apoptotic sperm into the oocyte. sperm with high negative surface electrical charge, named “zeta ...

2006
Nicolai Petkov Enrique Alegre Michael Biehl Lidia Sánchez

We consider images of boar spermatozoa obtained with an optical phase-contrast microscope. Our goal is to automatically classify single sperm cells as acrosome-intact (class 1) or acrosome-reacted (class 2). Such classification is important for the estimation of the fertilization potential of a sperm sample for artificial insemination. We segment the sperm heads and compute a feature vector for...

Journal: :Proceedings. Biological sciences 2014
Mathew Oliver Jonathan P Evans

Sperm chemoattraction, where sperm locate unfertilized eggs by following a concentration gradient of egg-derived chemoattractants, has been widely documented across numerous taxa. While marine invertebrates are favoured models for understanding the underlying mechanisms of sperm chemoattraction, the evolutionary forces underpinning the process remain enigmatic. Here, we show that in mussels (My...

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