نتایج جستجو برای: annual reproductive cycle

تعداد نتایج: 466005  

Journal: :Journal of environmental biology 2007
Pratap B Singh Vandana Singh

The catfish, H. fossilis were exposed to endosulfan for 30 days at sub-lethal concentration (0.002 ppm) during different phases of its annual reproductive cycle. Its impact on total (TP) and different phospholipids- phosphatidylcholine (PC), phosphatidylserine (PS), phosphatdylinositol (Pl) and phosphatidylethanolamine (PE) were measured in liver plasma and ovary. On pesticide exposure, during ...

2012
In Joon Hwang Sung Yeon Kim Hyung Bae Kim Hea Ja Baek

We investigated the changes in plasma sex steroid hormones, testosterone (T), estradiol-17β (E2), 17,20β -dihydroxy-4-pregnen-3-one (17α20βP), 11-ketotestosterone (11KT) and cortisol levels from ribbed gunnel, Dictyosoma burgeri in associated with annual reproductive cycle. The gonadosomatic index (GSI) of females increased from November, peaked in February and decreased rapidly from March. The...

Journal: :Mathematical biosciences and engineering : MBE 2014
Kaitlin Sundling Gheorghe Craciun Irvin Schultz Sharon Hook James Nagler Tim Cavileer Joseph Verducci Yushi Liu Jonghan Kim William Hayton

The rainbow trout endocrine system is sensitive to changes in annual day length, which is likely the principal environmental cue controlling its reproductive cycle. This study focuses on the endocrine regulation of vitellogenin (Vg) protein synthesis, which is the major egg yolk precursor in this fish species. We present a model of Vg production in female rainbow trout which incorporates a biol...

Journal: :Journal of morphology 2000
D M Sever T J Ryan T Morris D Patton S Swafford

This article is the first ultrastructural study on the annual oviducal cycle in a snake. The ultrastructure of the oviduct was studied in 21 females of the viviparous natricine snake Seminatrix pygaea. Specimens were collected and sacrificed in March, May, June, July, and October from one locale in South Carolina during 1998-1999. The sample included individuals: 1) in an inactive reproductive ...

2009
R. J. VAN AARDE

The Cape porcupine Hystrix africaeaustralis is a large (12-18 kg) nocturnal hystricomorph rodent occurring throughout southern Africa where it is sometimes used as a source of food and often regarded as a nuisance by crop-producing fanners. They live in family groups, these generally comprising an adult male, adult female and varying numbers of offspring of successive litters. Reproduction is c...

2015
Chiara Marchini Valentina Airi Roberto Fontana Giada Tortorelli Marta Rocchi Giuseppe Falini Oren Levy Zvy Dubinsky Stefano Goffredo Chaolun Allen Chen

The variety of reproductive processes and modes among coral species reflects their extraordinary regeneration ability. Scleractinians are an established example of clonal animals that can exhibit a mixed strategy of sexual and asexual reproduction to maintain their populations. This study provides the first description of the annual reproductive cycle and embryogenesis of the temperate species ...

Journal: :Proceedings. Biological sciences 2004
D Ryan Norris Peter P Marra T Kurt Kyser Thomas W Sherry Laurene M Ratcliffe

Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, we show that the reproductive success of a long-distance migratory bird is influenced by the quality of habitat located thousands of kilometres away on tropical wintering grounds. For male American red...

2008
D. Ryan Norris Peter P. Marra T. Kurt Kyser Thomas W. Sherry Laurene M. Ratcliffe

Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, we show that the reproductive success of a long-distance migratory bird is influenced by the quality of habitat located thousands of kilometres away on tropical wintering grounds. For male American red...

Journal: :acta medica iranica 0
m. h. lotfi s. charkhatti s. shobairi

breast cancer is the most common malignancy in women in many parts of the world. the risk factors for breast cancer cover a broad range of conditions, from age to complex genetic alterations. present data is showing an increase in the annual incidence rates of disease and it is ranked as the first recorded malignancies among iranian women after 1999. to study the association of reproductive and...

Journal: :Conservation physiology 2016
Warren K Hansen Lisa J Bate Devin W Landry Olivier Chastel Charline Parenteau Creagh W Breuner

Understanding sources of reproductive variation can inform management and conservation decisions, population ecology and life-history theory. Annual reproductive variation can drive population growth rate and can be influenced by factors from across the annual cycle (known as carry-over effects). The majority of studies, however, focus solely on the role of current environmental events. Past ev...

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