Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 ± 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.     

Evaluation of analgesic and physiologic effects of epidural morphine administered at a thoracic or lumbar level in dogs undergoing thoracotomy

ObjectiveTo evaluate the analgesic and physiological effects of epidural morphine administered at the sixth and seventh lumbar or the fifth and sixth thoracic vertebrae in dogs undergoing thoracotomy.Study designProspective, randomized, blinded trial.AnimalsFourteen mixed-breed dogs, weighing 8.6 ± 1.4 kg.MethodsThe animals received acepromazine (0.1 mg kg^?1) IM and anesthesia was induced with propofol (4 mg kg^?1) IV. The lumbosacral space was punctured and an epidural catheter was inserted up to the region between the sixth and seventh lumbar vertebrae (L, n = 6) or up to the fifth or sixth intercostal space (T, n = 8). The dogs were allowed to recover and after radiographic confirmation of correct catheter position, anesthesia was reinduced with propofol IV and maintained with 1.7% isoflurane. Following stabilization of monitored parameters, animals received morphine (0.1 mg kg^?1) diluted in 0.9% NaCl to a final volume of 0.25 mL kg^?1 via the epidural catheter, and after 40 minutes, thoracotomy was initiated. Heart rate and rhythm, systolic, mean and diastolic arterial pressures, respiratory rate, arterial hemoglobin oxygen saturation, partial pressure of expired CO₂ and body temperature were measured immediately before the epidural administration of morphine (0 minute) and every 10 minutes during the anesthetic period. The Melbourne pain scale and the visual analog scale were used to assess post-operative pain. The evaluation began 3 hours after the epidural administration of morphine and occurred each hour until rescue analgesia.ResultsThere were no important variations in the physiological parameters during the anesthetic period. The post-operative analgesic period differed between the groups, being longer in T (9.9 ± 1.6 hours) compared with L (5.8 ± 0.8 hours).ConclusionsThe use of morphine, at a volume of 0.25 mL kg^?1, administered epidurally over the thoracic vertebrae provided longer lasting analgesia than when deposited over the lumbar vertebrae.Clinical relevanceThe deposition of epidural morphine provided longer lasting analgesia when administered near to the innervation of the injured tissue without increasing side effects.     

Tolerance of Juvenile Flatfish Paralichthys orbignyanus to Acid Stress

Abstract.— The tolerance of juvenile flatfish Paralichthys orbignyanus to acid stress, was studied in 30-L plastic tanks using ten flatfishes (95 ± 13 g) per treatment. Water pH was monitored every 3 h and re-adjusted to the test pH using either HCl or NaOH. The photoperiod was fixed at 12L:12D, water temperature at 23 ± 0.8 C, and salinity at 30 ppt. Fish survival and ventilatory rate were monitored daily. At pH 4.0, we observed 100% mortality and ventilation rates different from controls. At pH 5.2, there was 100% survival even after 96 h. However, ventilation rate was higher than in controls. At pH equal or higher than 6.0, we observed 100% survival and normal ventilation rates. The estimated pH which would kill 50% of test organisms were: 4.51, 4.50 and 4.40 after 48, 72, and 96 h of experiment, respectively. These results show that juvenile flatfish are relatively tolerant to acid stress.     

Marine research,resources and conservation in the Azores

• 1 A history of marine research on the Azores is outlined. Until two decades ago most oceanic and littoral marine studies had been carried out by foreign scientists. Studies by Azorean scientists started to increase in the early 1980s when the University of the Azores was created.
• 2 Ocean circulation in this part of the Atlantic is described as a background for biogeography and diversity. The picture emerges that Azores is a ?meeting point’? for shallow water marine fauna and flora of different origins.
• 3 The species composition of one of the best studied groups of organisms, the fish, is compared between locations in the northeastern Atlantic. The work on fish is also compared with other well studied groups (algae and hydroids) to highlight the interest of the Azores as a natural biogeographical experiment.
• 4 Studies of marine resources began less than two decades ago. The development of demersal fisheries is described focusing on the switch from small-scale artisanal fishing to more commercial fisheries.
• 5 Conservation of species and legislation in force for molluscs, crustaceans, fishes, marine turtles, seabirds and marine mammals are summarized.
• 6 Protected marine areas already designated are defined, as well as new areas recommended.
• 7 The paper concludes with a discussion of current threats and future management strategies.

     

Selective control of polyamide dyeing with acid dyes using hydroxypropyl-β-cyclodextrin

The effect of hydroxypropyl-β-cyclodextrin (HPβCD) in the dyeing of polyamide fabric was investigated under conditions that mimic industrial dyebaths where dye mixtures are used. The dyes used were Telon Red BN, Telon Yellow A-2R, and Telon Blue RR. The blue dye complexed with HPβCD whereas the other dyes did not do so under the conditions used. The dyeing results were compared with those obtained using a traditional retarding agent, Albegal B. The exhaustion dyeing data showed that HPβCD mainly affected the dyeing behavior of the blue dye that became encapsulated. In the case of the yellow and red dyes, changes in the overall kinetics of dyeing were observed, resulting in modified exhaustion profiles. In comparison, Albegal B retarded the blue dyeing process and increased the rate of exhaustion of the yellow dye while the exhaustion curve of red dye remained unchanged. The color uniformity of the dyed polyamide was improved when HPβCD was used. This resulted from the more controlled exhaustion rate during the critical phase of the dyeing process.     

Deposition of gold mining tailings in tropical soils: metal pollution and toxicity to earthworms

Journal of Soils and Sediments - This study consists of the evaluation of metals acute toxicity levels taking into consideration a hypothetic scenario of dam breaking and land deposition of two...     

The effects of light and temperature on the photosynthesis of the Asparagopsis armata tetrasporophyte (Falkenbergia rufolanosa), cultivated in tanks

The integrated aquaculture of the tetrasporophyte of Asparagopsis armata Harvey (Falkenbergia rufolanosa) using fish farm effluents may be viable due to the species high capacity of removing nutrients and its content of halogenated organic compounds with applications on the pharmaceutical and chemical industries. In order to optimize the integrated aquaculture of F. rufolanosa, we followed the daily variation of the potential quantum yield (F_v/F_m) of PSII on plants cultivated at different biomass densities and different total ammonia nitrogen (TAN) fluxes to check if they are photoinhibited at any time of the day. Moreover, the photoinhibition under continuous exposure to highly saturating irradiance and its potential for subsequent recovery in the shade was assessed. The potential for year round cultivation was evaluated by measuring rates of O₂ evolution of plants acclimated at temperatures ranging from 15 to 29 °C, the temperature range of a fish farm effluent in southern Portugal where an integrated aquaculture system of F. rufolanosa was constructed.Photoinhibition does not seem to be a major constrain for the integrated aquaculture of F. rufolanosa. Only when cultivated at a very low density of 1.5 g fresh weight (FW) l^− 1 that there was a midday decrease in maximal quantum yield (F_v/F_m). At densities higher than 4 g FW l^− 1, no photoinhibition was observed. When exposed to full solar irradiance for 1 h, F. rufolanosa showed a 33% decrease in F_v/F_m, recovering to 86% of the initial value after 2 h in the shade. A midday decline of the F. rufolanosa F_v/F_m was also observed under the lowest TAN flux tested (∼6 μM h^− 1), suggesting that this fast and easy measurement of fluorescence may be used as a convenient diagnostic tool to detect nutrient-starved unbalance conditions of the cultures. Maximum net photosynthesis peaked at 15 °C with 9.7 mg O₂ g dry weight (DW)^− 1 h^− 1 and remained high until 24 °C. At 29 °C, the net oxygen production was significantly reduced due to a dramatic increase of respiration, suggesting this to be the species' lethal temperature threshold.Results indicate that F. rufolanosa has a considerable photosynthetic plasticity and confirm it as a good candidate for integrated aquaculture at temperatures up to 24° C and cultivation densities of at least 5 g FW l^− 1. When cultivated at these densities, light does not penetrate below the first few centimetres of the surface zone. Plants circulate within the tanks, spending around 10% of the time in the first few centimetres where they are able to use efficiently the saturating light levels without damaging their photosynthetic apparatus.     

Efficacy of furunculosis vaccines in turbot, Scophthalmus maximus (L.): evaluation of immersion, oral and injection delivery

The commercial furunculosis vaccine Aquavac Furovac 5 and an autogenous vaccine, based on the challenge strain, induced immune protection in turbot, Scophthalmus maximus (L.), as shown in challenge tests 120 days post-immunization by injection (relative percentage of survival, RPS = 72-99%). This protective effect lasted for at least 6 months post-immunization at appreciable levels (RPS = 50-52%). Neither the autogenous vaccine nor the commercial vaccine was able to induce significant levels of protection against Aeromonas salmonicida in turbot when administered by immersion. Antibody levels were high or moderate in fish vaccinated by injection with the different vaccines and very low in fish vaccinated by immersion. The field results show that delivering an oral boost after the primary vaccination by injection did not enhance protection of turbot against furunculosis and that water-based (autogenous vaccine) and oil adjuvanted (Alpha Ject 1200) vaccines administered by injection conferred similar levels of protection (RPS > 80%) in turbot.     

Size selectivity of the Spisula solida dredge in relation to tooth spacing and mesh size

A study was undertaken on the northwestern coast of Portugal to evaluate the selectivity effect of both tooth spacing and mesh size on the catch of the white clam (Spisula solida). Two typical clam dredges, equipped with different tooth spacing and mesh size, were towed side by side. Three tooth spacing (20, 40 and 60 mm) and three mesh sizes (35, 40 and 50 mm) were investigated. The dredge selectivity experiments were performed by attaching a cover bag with a 20 mm mesh to the gear. Individual hauls were analysed by the SELECT model. The Fryer’s mixed model of between-haul variation was also applied to data. The results showed that the space between teeth does not have an effect on selectivity. Tooth length was directly related to the dredge’s capture efficiency. The only factor that contributed to dredge size selection was mesh size. The 50% retention lengths estimated for mesh sizes 30, 40 and 50 mm were 25.68, 26.35 and 31.94 mm, respectively. For all mesh sizes, very narrow selection ranges were observed. The most appropriate mesh size to be enforced within the Portuguese northwestern S. solida fishery should be 40 mm.