Suspended sediment dynamics during flushing flows in a large impounded river (the lower River Ebro)

Purpose

The aim of this work was to improve the understanding of the spatial and temporal dynamics of suspended sediment transport during flushing flows in a large regulated river, the lower River Ebro (NE Spain).

Materials and methods

Relationships between sediment and discharge (i.e. discharge (Q)–suspended sediment concentrations (SSC)) were examined during six flushing flows using continuous discharge and turbidity records obtained at six monitoring sections distributed along the lower Ebro River for the 2008–2011 period.

Results and discussion

Analyses revealed marked spatial and temporal patterns. At the spatial scale, the Q–SSC relationships were mostly influenced by the different routing velocity of discharge and sediment waves. At the upstream sections, the sediment peak usually preceded peak discharge (i.e. clockwise loop); however, flow routing through the 85-km channel length tends to increase the lag between them, modifying the hysteresis towards counter-clockwise patterns in the downstream direction. At the temporal scale, the season when the artificial releases were performed strongly influenced the sediment availability, with similar-magnitude flushing flows generating higher sediment peaks in autumn than in spring.

Conclusions

These results are of great interest in order to reinforce the flushing flows programme in the lower Ebro River, so as to help achieve the sustainability of the riverine and deltaic ecosystems.     

Effect of administration of a controlled-release monensin capsule on incidence of calving-related disorders, fertility, and milk yield in dairy cows

OBJECTIVE: To determine the effect of a controlled-release monensin capsule administered at cessation of lactation on incidence of calving-related disorders, fertility, and milk yield in dairy cows. ANIMALS: 290 dairy cows treated with monensin and 290 untreated control cows. PROCEDURE: Treated cows received a capsule that released monensin at 335 mg/d for 95 days. Incidence of calving-related disorders; daily milk yield up to 20 days postpartum; test-day milk yield, fat, protein, and mature-equivalent 305-day milk production; and body condition score at calving were determined. Reproductive variables were conception rate at first service, pregnancy rate, and calving-to-conception interval. RESULTS: Cows treated with monensin were 2.1 times as likely to develop dystocia and 0.8 times as likely to develop metritis as control cows. For milk yield, there was an interaction of treatment X time X parity. In multiparous cows, monensin significantly improved milk yield at test days 4 and 7. In addition, monensin increased body condition score at calving. CONCLUSIONS AND CLINICAL RELEVANCE: Despite increasing the likelihood of developing dystocia and metritis, administration of monensin improved the lactational performance of multiparous cows and may be a promising additive for use at the time of cessation of lactation.     

Inhibition of pheromone response in Sesamia nonagrioides by the pheromone of the sympatric corn borer, Ostrinia nubilalis

Sesamia nonagrioides Lef. and Ostrinia nubilalis (Hübn.) are two corn borers present in the Mediterranean area that share a similar feeding habitat. The female sex pheromones of the two species consist of (Z)-11-hexadecenyl acetate, (Z)-11-hexadecen-1-ol, (Z)-11-hexadecenal and dodecyl acetate (77:8:10:5 w/w) and (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate (97:3 w/w) respectively. Although the pheromones share no common components, previous work had shown the inhibition of the response by O. nubilalis males to their own pheromone owing to the presence of S. nonagrioides pheromone. In this study, the pheromone of O. nubilalis and its two components separately were shown to inhibit the attraction of S. nonagrioides males to the synthetic female pheromone in both laboratory wind-tunnel bioassay and field trapping studies. In the wind tunnel, the number of contacts of S. nonagrioides males with the source were significantly (P < 0.05) reduced by the single pheromone components of O. nubilalis. In the field, the addition of 1% of O. nubilalis pheromone significantly (P < 0.05) reduced the catches of S. nonagrioides males. The components of both pheromones also elicited electroantennographic responses from antennae of male S. nonagrioides moths. The ecological consequences and the possibilities of applying this cross-inhibition for mating disruption techniques are discussed.     

Mechanism of crumb toughening in bread-like products by microwave reheating

Comparing breads reheated in conventional and microwave ovens revealed that the latter considerably toughens the crumb texture when internal boiling is induced. Moisture loss in itself has a relatively minor toughening effect. The major changes, caused by boiling, occur only in systems with starch concentration in excess of a threshold level of about 37% (wet basis). Substantially greater amounts of amylose are leached out of the granules in the case of sustained boiling during microwave heating, as compared to conventional oven heating. The free amylose solution is being "pushed" by the generated steam pressure toward the air-cell wall interface. A rich amylose phase is accumulated at that interface and over the granules. Upon cooling, the amylose undergoes rapid phase changes; thus, toughening is apparent in a relatively short time after heating. Minimizing the textural deleterious effects in microwave reheating of bread-like products should entail (a) preventing or minimizing internal boiling, (b) diluting of the starch concentration below the threshold level, (c) interfering with the amylose phase change by using complex forming agents.     

Die Anwendung von Triphenyltetrazoliumchlorid zur Schnellprüfung der Keimfähigkeit bei Samen vonCoffea arabica L.

Zusammenfassung Durch Anwendung des TTC-Schnelltestes wurde versucht, ein praktisch brauchbares Keimprüfungsverfahren für Kaffeesamen zu entwickeln. Es wird eine Routinemethode zur Keimprüfung mit TTC vorgeschlagen, die mit isolierten Embryonen von Kaffee arbeitet. Dieses Verfahren wurde an 4 verschiedenen Samenproben von Kaffee überprüft. Die Übereinstimmung der Ergebnisse aus den Keimprüfungen, die vergleichend unter natürlichen Bedingungen vorgenommen wurden, mit denen des TTC-Testes war gut, so daß eine praktische Anwendung des Verfahrens für den Kaffeeanbau gerechtfertigt erscheint.

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Application of triphenyltetrazolium chloride for rapid testing of the viability of seeds fromCoffea arabica L.

Summary Using TTC we tried to develop a useful method for testing the germination capability of coffee seeds. A routine test method for germination using TTC is suggested, which works with isolated embryos of the coffee seeds. This method was tested with 4 different samples of coffee seeds and compared with the germination of coffee seeds at natural conditions. The agreement of the results from both germination tests was very good. Therefore the application of the test with TTC is proposed for the practical coffee farming.

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Effects of myrtle (Myrtus communis L.) essential oils as dietary antioxidant supplementation on carcass and meat quality of goat meat

Despite the fact that the use of rosemary and thyme residues and essential oils in animal feeding was widely documented, that of myrtle is scarce. To test the hypothesis that myrtle essential oils (MEOs) could improve goats' carcass characteristics and meat quality traits, twenty-one male goats received a ration consisted of 40% oat hay and 60% concentrate. Experimental goat kids received the control diet supplemented with 0, 0.3 and 0.6% of myrtle essential oils (MEOs) for C, Myrt1 and Myrt2 groups respectively. The administration of MEO did not improve the daily DM intake (p > 0.05). Kids of C and Myrt2 groups had higher average daily gain than Myrt1 group (75 versus 55 g). The goats slaughtered at 19.9 kg of weight did not differ (p > 0.05) in carcass weights and carcass yield in terms of commercial dressing percentage (CDP = 41%) and real dressing percentage (RDP = 52%). The administration of MEO increased the meat polyphenol content, being higher in both Myrtle groups (87 versus. 56 μg gallic acid equivalents g^-1 fresh matter, p < 0.05). Myrtle EO administration protected kids’ meat against oxidation (0.48 versus. 0.91 mg MDA/kg of meat for Myrtle and C groups, respectively, at the 9th day of storage; p < 0.05). It could be useful to include MEO as a dietary supplement in goats’ rations since it improves meat's oxidative status without negative effects on FA profile.