Evaluating urban surface water quality in Luton.

Using a single numerical value to indicate the quality of water, a so-called Water Quality Index (WQI) is a well-established way of rating the overall water quality status of a given water body. During the last few years, researchers in the water sector have developed different such indices to address their specific needs. In this study, we attempt to obtain a WQI formula suited for evaluating the water quality of the River Lea.

Impact of cryoprotectants and cryopreservation on metabolic activity and cytoskeleton proteins of zebrafish (Danio rerio) ovarian fragments.

Cryopreservation of reproductive cells and tissues of aquatic species offers many benefits to the field of conservation, aquaculture and biomedicine. Although cryopreservation of fish sperm has been successfully achieved, cryopreservation of embryos and oocytes remains unsuccessful. Several studies have been undertaken on cryopreservation of isolated fish ovarian follicles at different stages, although the protocols used lead to a compromised viability.

Ultrasound enhanced methanol penetration of zebrafish (Danio rerio) embryos measured by permittivity changes using impedance spectroscopy.

Studies on permittivity changes in fish embryos measured by impedance spectroscopy after ultrasound treatment during exposure to cryoprotectant is reported here for the first time. The permittivity changes of zebrafish embryos in cryoprotectant solutions before and after ultrasound treatment were measured using impedance spectroscopy. Zebrafish (Danio rerio) embryos at 50% epiboly stage were exposed to 2 M methanol for 25 min before ultrasound treatment for 5 min at 22 degrees C.

Study on fish embryo responses to the treatment of cryoprotective chemicals using impedance spectroscopy.

Investigations using electrical impedance spectroscopy to measure the responses of fish embryos to the cryoprotective chemicals, methanol and dimethyl sulphoxide (DMSO), were carried out. Zebrafish (Danio rerio) embryos were used as a model to study the newly proposed technique. The normalised permittivity and conductivity changes of the embryos were measured continuously over a 20-min period in a customised embryo-holding chamber.

The effect of external medium composition on membrane water permeability of zebrafish (Danio rerio) embryos.

The effect of external medium composition on chorion and plasma membrane permeability of zebrafish (Danio rerio) embryos was investigated in this study. Initially, survival of embryos spawned into varying strengths (10-40%) of Hank's solution (HBSS) was assessed. Development and hatching rates for embryos spawned into 30% and 40% HBSS were significantly lower than those obtained with embryos spawned into system water.

Studies on membrane permeability of zebrafish (Danio rerio) oocytes in the presence of different cryoprotectants.

Investigation into fish oocyte membrane permeability is essential for developing successful protocols for their cryopreservation. The aim of the present work was to study the permeability of the zebrafish (Danio rerio) oocyte membrane to water and cryoprotectants before cryopreservation protocol design. The study was conducted on stage III and stage V zebrafish oocytes.

Effect of cryopreservation on mitochondrial DNA of zebrafish (Danio rerio) blastomere cells.

Cryopreservation has been extensively used in human reproductive medicine, aquaculture and conservation programmes for endangered species. However, despite the growing successes of cryopreservation, post-thaw recovery of reproductive and embryonic cells very often remains poor. Many studies have been devoted to the mechanisms of cryodamage.

Studies on chilling sensitivity of zebrafish (Danio rerio) oocytes.

Human activity in the last few decades has had a devastating effect on the diversity of fresh water and marine fish. Further decline of fish population may have serious economic and ecological consequences. One of the most promising techniques to preserve fish population is to cryopreserve their germ cells.

Effect of DNA repair inhibitor (3-aminobenzamide) on genetic stability of loach (Misgurnus fossilis) embryos derived from cryopreserved sperm.

Semen cryopreservation is widely used in clinical medicine, agriculture, aquaculture and biomedical research, but it is an inefficient technique that induces extensive cytoplasmic damage and loss of fertilising ability. Whether any genetic damage (i.e.

Effects of methanol and developmental arrest on chilling injury in zebrafish (Danio rerio) embryos.

Stage-dependent chilling sensitivity has been reported for many species of fish embryos. Most of these studies reveal that developmental stages beyond 50% epiboly are less sensitive to chilling, but the chilling sensitivity accelerates rapidly at subzero temperatures. In this study, the effects of methanol and developmental arrest on chilling injury were studied using zebrafish (Danio rerio) embryos at 64-cell, 50% epiboly, 6-somite, prim-6 and long-bud stages.

Studies on cryopreservation of luc gene transfected bluegill sunfish fibroblast cell line.

The effect of cryopreservation on the survival of luc gene transfected bluegill sunfish fibroblast (BF-2) cells was investigated. Propane-1,2-diol was found to be the least toxic cryoprotectant when compared with DMSO and methanol. Both propane-1,2-diol and DMSO are effective in protecting cells from freezing damage.