Sustainable aquaculture through water recycling

The discharge of nutrient rich effluent from aquaculture systems into coastal waters is cause for concern. Direct filtration of aquaculture wastewater, using floating medium and sand with in line flocculation, and biological filtration using activated carbon, has the potential to improve water quality for recycling within aquaculture systems. This study looked at the performance of laboratory scale dual media and activated carbon filters in suspended solids and nutrient removal in the treatment of aquaculture wastewater. The dual media filter, with flocculant FeCl3 of 9mg/L, functioned best at a velocity of 7mJh with low headloss, and good turbidity and phosphorus removal (80% and 53% respectively). The activated carbon filter removed ammonia (84%) and nitrite (71 %) in the process of nitrification with a five-hour hydraulic retention time. This paper reports preliminary results from a longer term sustainable aquaculture project.<br /

ÉTUDE DU NOMBRE D'OVULATIONS APRES SUPEROVULATION INDUITE PAR PMSG CHEZ TROIS SOUCHES DE RATTES ADULTES

International audienc

Analyse biométrique de l'index de marquage des cellules folliculeuses et de la taille des ovocytes des follicules primordiaux d'ovaire de ratte adulte cyclique

International audienc

ÉTUDE DE LA FORMATION DE L'ANTRUM DANS LES FOLLICULES DE L'OVAIRE DE RATTE ET DE VACHE NORMALES OU STIMULÉES PAR PMSG

International audienc

Technological advances in aquaculture farms for minimal effluent discharge to oceans

Aquaculture is an expanding, high value primary industry in many countries including Australia. At the same time, the environmental sustainability of aquaculture is attracting increasing attention, especially in Australia. One of the major environmental issues facing aquaculture in the 21st century is the management of discharge of nutrient-rich waters from land-based aquaculture systems into coastal waters, which affects the marine environment. It is of great concern especially for the world renowned Great Barrier Reef (GBR) where the nutrient discharge into the coastal waters in its proximity, and subsequent algal growth, could cause damage to the corals and its fragile ecosystem. Therefore, load-based licences are issued to aquaculture farms near GBR to meet the stringent effluent discharge requirements and this has forced the aquaculture industry located near the GBR, such as those in North Queensland, to look ahead and do something via cleaner production. This paper deals with several technologies that are being tested in various aquaculture farms especially in North Queensland in order to treat the aquaculture effluent for the purpose of reuse as well as the legal and environmental drivers that led to the development and implementation of these new technologies

FOLLICULOGENÈSE CHEZ LA VACHE

International audienc

Treatment of Sickle cell disease's hip necrosis by core decompression: A prospective case-control study

Introduction: The young age of patients, total arthroplasties complications risks, and implant costs justify evaluation of the results of core decompression in the treatment of sickle-cell disease avascular necrosis of the femoral head (ONFH). Hypothesis: In sickle-cell disease necrosis, core decompression offers good relief from pain and delays the use of total arthroplasty in comparison to a conservatively treated control group by a simple non-weight bearing protocol. Materials and Methods: From 1994 to 2008, among 215 drepanocytic adults, 42 patients (22 genotype SS, 20 genotype SC; 15 men, 27 women) presented symptomatic ONFH. We report the data from a prospective study of two patients' groups: a non-operated group (16 patients aged 36.5 ± 6.5 years, 23 hips) and an operated group (26 patients aged 30.3 ± 2.8 years, 42 hips). The results were considered on the basis of change in clinical status according to the numeric evaluation of pain scale, the functional score of Merle d'Aubigné-Postel (MAP), the radiological progression of lesions, and the time delay to total arthroplasty. Results: Twenty-three hips were conservatively treated by discharge (a pair of canes). After a follow-up period of 13.4 ± 0.5 years, no pain improvement was noted (p = 0.76), and MAP score was unchanged (p = 0.27). Out of 23 hips managed by discharge, 9 stage IV hips (degenerative arthritis, 39.1%) underwent arthroplasty after an average delay of 2.6 ± 2.4 years. Forty-two hips were treated by core decompression. The duration of follow-up was 11.3 ± 1.8 years. Postoperatively, pain reduction and MAP score improvement were significant in 39 out of 42 hips (93%, p < 0.0001). Twenty-nine out of these 42 hips had a favorable evolution. Ten hips (23.8%) progressed to total arthroplasty, after a period of 7.4 ± 2.7 years, longer than the one of the non-operated group (p = 0.0007). By comparing the two groups (operated and non-operated), the benefit of core decompression appeared very significant (p < 0.0001). In addition to allocating Patients osteonecrosis stages, the Koo and Kim Index estimated the severity and evolution of necrotic lesions in both groups. It indicated decline in the non-operated group (p = 0.002) and improvement for operated patients (p = 0.0002). Discussion: Core decompression had a favorable clinical and radiological outcome superior to surgical abstention. Stages I and II ONFH remained stable after drilling, necessitating no arthroplasty (considered as a failure of drilling). The Koo and Kim Index above 30° in the non-operated group was a significant indicator of lesions degradation (p = 0.002). In addition to the indolence obtained by core decompression, the benefit of drilling was manifested by the prolonging the adjournment before arthroplasty end-point. It was respectively 7.4 ± 2.7 years in the operated group versus 2.6 ± 2.4 years in the non-operated group (difference of 4.8 years, p < 0.01). Conclusion: The technique of core decompression remains a valid option place in the treatment sickle-cell disease avascular necrosis of the femoral head (ONFH). It may be especially recommended in under-equipped regions where drepanocytosis and its osteo-articular complications are frequent. Level of Evidence: Level III case-control therapeutic study. © 2009.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Self-made shelters protect spiders from predation

Many animals modify their environments, apparently to reduce predation risk, but the success of such endeavors, and their impact on the density and distribution of populations, are rarely rigorously demonstrated. We staged a manipulative experiment to assess the effectiveness of self-made shelters by web spiders as protection from natural enemies. Scincid lizards were included or excluded from 21 replicated 200-m2 plots, and spiders therein were classified as exposed or sheltered, depending on whether they were uncovered in their web or hidden in cocoons, leaves/debris, or burrows. We found that exposed spiders were greatly affected by the presence of predatory scincid lizards, whereas sheltered spiders were not. More specifically, lizards, which forage close to the ground, reduced the abundance of exposed spiders by two-thirds but had no effect on the abundance of sheltered spiders. Sheltered spiders were able to avoid predation and share space with lizards, suggesting that shelter construction is a mechanism for reducing predation risk and has important population consequences