Effect of dietary water on growth of dentex <Emphasis Type="Italic">Dentex dentex</Emphasis>

ABSTRACT:   This study is concerned with the effect of hyrdated diets on growth and feed performance of Dentex dentex . Three levels of dietary water were tested: 7%, 20% and 40%. For the 7% level a commercial feed was used and the 20% and 40% water levels were obtained after adding an appropriate amount of deionized water to the commercial feed and mixing the pellets well. The diets were offered to fish by self-feeders, by which fish were allowed continuous access to diets after activating the self-feeders; by belt feeders, by which the diets were fed continuously and in excess over a 12 h interval; and by hand to apparent satiation two times a day. After 151 days of feeding, the group fed on the 20%-water diet showed significantly ( P  < 0.05) higher growth rate than the 7 and 40% groups, while no significant differences were observed in feed conversion rate or daily feed consumption. The means of feed delivery did not influence growth rate. Self-feeder, belt and hand feeding all gave comparable growth. Fish fed the more condensed 7%-water diet had smaller stomachs than fish fed the larger volume 40%-water diet. In the stomach, all groups of fish hydrated their digesta within 2 h after feeding to a moisture content of around 60%. Apparently no difference in digestive process was observed between groups. It was concluded that the addition of water in diet at the level of 20% has a beneficial effect on dentex growth.     

母猪泌乳期饲喂同仔猪生长之间的关系

最近有顾客向笔者提出了一个问题 :增加母猪泌乳期采食量有什么价值 ?这使我想起 ,人们比较了解增加母猪泌乳期采食量对母猪繁殖性能的好处 ,却不太了解这对仔猪生长有多大好处。毫无疑问 ,我们都知道 ,增加泌乳母猪的采食量可改善母猪的繁殖性能。母猪在泌乳期内体脂和机体蛋白质损失得越少 ,则断奶后恢复发情就越快 ,下一胎的窝产仔数往往也越大。对猪群生产记录的研究分析表明 ,一头母猪在泌乳期间每丧失 1千克体重 ,则断奶后发情就推迟一天。同样 ,母猪泌乳期间每丧失 1 0 %体脂 ,下一胎的窝产仔数就减少一头。增加母猪泌乳期采食量对仔…     

Promoting axon regeneration in the adult CNS by modulation of the PTEN/mTOR pathway

The failure of axons to regenerate is a major obstacle for functional recovery after central nervous system (CNS) injury. Removing extracellular inhibitory molecules results in limited axon regeneration in vivo. To test for the role of intrinsic impediments to axon regrowth, we analyzed cell growth control genes using a virus-assisted in vivo conditional knockout approach. Deletion of PTEN (phosphatase and tensin homolog), a negative regulator of the mammalian target of rapamycin (mTOR) pathway, in adult retinal ganglion cells (RGCs) promotes robust axon regeneration after optic nerve injury. In wild-type adult mice, the mTOR activity was suppressed and new protein synthesis was impaired in axotomized RGCs, which may contribute to the regeneration failure. Reactivating this pathway by conditional knockout of tuberous sclerosis complex 1, another negative regulator of the mTOR pathway, also leads to axon regeneration. Thus, our results suggest the manipulation of intrinsic growth control pathways as a therapeutic approach to promote axon regeneration after CNS injury.     

Factors affecting the efficacy of non-fumigant nematicides for controlling root-knot nematodes

Second-stage juveniles (J2) and egg masses of root-knot nematodes as well as root debris heavily infected by the latter were exposed for different periods of time to six different doses of the nematicides cadusafos and fenamiphos. The efficacy of the nematicides increased significantly with increasing exposure time. Both nematicides were more effective against J2, although they could not provide acceptable control of J2 inside egg masses or heavily galled root debris. The effect of different application strategies on the efficacy and persistence of certain nematicides was also assessed in a field study. Cadusafos, fenamiphos, fosthiazate and oxamyl were applied in field micro-plots either as a single full dose at the time of crop establishment or as multiple reduced-rate applications at 14-day intervals throughout the cropping period, and their efficacy and persistence were determined using bioassays and analytical studies. Fosthiazate was the most efficient nematicide studied, and this was mainly attributed to its long soil persistence. Oxamyl also provided adequate nematode control for the first 48-56 days after its application, regardless of the application method used and its relatively rapid field dissipation. Fenamiphos and cadusafos failed to provide adequate nematode control, although cadusafos was the most persistent of the nematicides tested. The failure of fenamiphos to provide adequate nematode control was mainly attributed to its rapid degradation by soil micro-organisms, which were stimulated after its repeated low-rate application at 14-day intervals. In contrast cadusafos failure was attributed to the inability of the nematicide to reduce nematode populations even at relatively high concentrations in soil.     

Method agreement between three different chambers for comparative boar semen computer‐assisted sperm analysis

The computer‐assisted sperm analysis (CASA) has become a standard laboratory tool. Although it contributes a lot to the objective sperm motility assessment, its measurements may be affected by many factors. The aim of the study was to evaluate the effect of chamber on boar semen CASA results. Totally, 100 extended (30 × 10⁶ sperm/ml) boar semen samples were analysed by CASA. Each sample was evaluated using Makler, Leja 4 chamber 20 μm and conventional glass slide/coverslip chambers (MC, LC and GSC, respectively). The differences in values between MC and LC and between MC and GSC were significantly positive (higher values for MC compared with LC and GSC) for total motility, progressive, rapid movement, VCL, VSL, VAP, STR and hyperactive, thus indicating a systematic effect. Between LC and GSC, the differences in many parameters (non‐progressive, progressive, slow, LIN, STR, hyperactive) were evenly distributed around zero, while in all other parameters the differences were significantly positive (higher values for LC compared with GSC), except for medium movement. Based on the estimated intraclass correlation coefficients, the method agreement between MC and LC and between LC and GSC was overall moderate to good, depending on the parameter; nonetheless, it was poor between MC and GSC. The limits of agreement between methods can vary considerably depending on the parameter and should be considered when comparisons between CASA measurements of different andrology laboratories or studies have to be performed.     

Evaluation of intra-articular injection of autologous platelet lysate (PL) in horses with osteoarthritis of the distal interphalangeal joint

Background: Regenerative medicine has become one of the most promising therapies of equine osteoarthritis. Platelet lysate (PL) is rich in bioactive proteins and growth factors that play a crucial role in tissue healing.

Objective: To evaluate the efficacy of intra-articularly injected autologous PL in equine athletes with naturally occurring osteoarthritis.

Animals and methods: Fifteen warmblood geldings aged 8–19 years with osteoarthritis of the distal interphalangeal joint were included in this study. They were randomly divided into two groups; 10 horses received intra-articular injections of PL and 5 of normal saline (controls). Before treatment, platelet-derived growth factor (PDGF) levels in basal plasma and prepared PL were estimated. Each joint was injected twice within a three-week period. Lameness was evaluated using the American Association of Equine Practitioners grading system, before treatment and 10 days after each intra-articular injection. Horses were examined fortnightly for one year. Radiographic examination was performed six months post-treatment. The generalized estimating equation test was used for statistical analysis.

Results: Acceptable levels of PDGF were detected in PLs (mean ± SD: 258.0 ± 52.3 pg/ml). The majority of horses (9/10) responded positively to PL treatment presenting lower lameness grades (p < 0.0005) compared to controls 10 days after the second injection, and returned to normal athletic activity. Radiographs revealed no changes in osteoarthritis lesions six months after treatment. One year post-injections, however, all horses relapsed to their initial degree of lameness.

Conclusion: Intra-articularly injected autologous PL is an efficient method for temporarily managing osteoarthritis of the distal interphalangeal joint in athletic horses.     

Proposed Indices for Assessing Soil Pollution Under the Application of Sludge

The assessment of soil pollution with heavy metals has been studied, based on experimental soil and plant analytical heavy metal data obtained by a pot experiment conducted during 2010?C2011 in a green house. A completely randomized block design was used, including the following sludge treatments (in tons per hectare): 0, 6, 12, 18, 24, 30, and (30+treated wastewater) in four replications. Lettuce (Lactuca sativa L.) var. longifolia was used as a test plant. Three indices were proposed, i.e., (1) elemental pollution index, (2) heavy metal load, and (3) total concentration factor. They were found to be linearly and statistically significantly related to the pollution load index, which was used as a reference index, and curvilinearly related to lettuce dry matter yield. It was concluded that the above indices could be used for the assessment of soil pollution level.     

Polycyclic aromatic hydrocarbons (PAHs) in marine sediments of the Hellenic coastal zone, eastern Mediterranean: levels, sources and toxicological significance

Purpose  

Polycyclic aromatic hydrocarbons (PAHs) are widespread in sediments, particularly near areas of intense human activities. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in major coastal areas of Greece that receive various pressures, investigate their sources and evaluate their potential toxicity by comparison against effects-based Sediment Quality Guidelines (SQG).