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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Gonadal Development and Sex Inversion in Saddleback Anemonefish Amphiprion polymnus Linnaeus (1758)) ผู้เขียน: Sukjai Rattanayuvakorn,  นายพิสุทธิ์ มังกรกาญจน์, ผู้ช่วยศาสตราจารย์ , นางอมรา ทองปาน, รองศาสตราจารย์, นางกรรณิกา ชัชวาลวานิช, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractGonadal development and sex inversion of saddleback anemonefish, Amphiprion polymnus were described. One-month juveniles had sexually undifferentiated gonads with primordial germ cells aggregated in groups, while two- to three-month juveniles displayed immature hermaphroditic gonads containing early developmental stages of both male and female germ cells, namely spermatogonia, primary spermatocytes, oogonia, and primary oocytes in chromatin-nucleolus stage. Spermatogenesis began at 4 months having testicular tissue comprising of spermatogenic cells in all developmental stages but ovarian cavity was first seen later at 5 months. The male region of ovotestis was peripheral, whereas the female region was more centrally located. There was no connective tissue between ovarian and testicular areas. Six-to 11-month fish had slightly larger ovotestes than those at previous age. Protandric sex inversion first occurred at 12 months. Sex change was characterized by degeneration of male germ cells, deposition of yellow-brown pigment and the formation of vitellogenic oocytes. Before spawning activity began, their gonads contained female germ cells in all stages with numerous vitellogenic oocytes, whereas functional males had both ovarian and testicular tissues. Most females of breeding pairs had mature oocytes in their gonads and began to spawn when their ages reached 14 months. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Sericin Recovery from Silk Cocoon Degumming Wastewater by a Membrane Process) ผู้เขียน:ทัศชา สนจุ้ย, ดร.ชลธิชา นุ่มหอม, รองศาสตราจารย์, ดร.อมรรัตน์ พรหมบุญ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractFlat sheet asymmetric polymeric membranes were prepared from a homogeneous solution of polysulfone (PSF) in N-methylpyrrolidone by the phase inversion process with various concentrations and molecular weights of polydioxolane (PDXL) ( Mn = 10,000 Da and 200,000 Da) and polyethylene glycol (PEG) ( Mn = 300, 2000, 4600 and 10,000 Da) as the polymeric additives. The surface morphology of the prepared membranes was investigated. The performance of the prepared membranes was tested by their use in the recovery of sericin from silk cocoon degumming wastewater. The effects of polymeric additives and transmembrane pressures (200, 300 and 400 kPa) were studied in terms of the permeate flux (PF), protein retention and molecular weight cut-off (MWCO) of sericin retention. Results showed that the PF and MWCO of the permeate increased but protein retention decreased with increasing concentration, molecular weight of both polymeric additives and transmembrane pressure. Hence, it clearly revealed that the morphological parameters and flux performance of the membranes have a significant inter-relationship with the concentration, molecular weight of both polymeric additives and transmembrane pressure. |
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