Metal leaching and toxicity of denitrifying woodchip bioreactor outflow—Potential reuse application

The denitrifying woodchip bioreactor is designed to remediate nitrate-rich water, including those produced from aquaculture effluents. Reuse of treated bioreactor outflows in recirculating aquaculture would offer considerable water savings and valuable alkalinity recuperation. However, such bioreactors may leach detrimental wood-bound contaminants, preventing outflow reuse. To determine water reuse potential, woodchip media from two hardwood species (white ash, Fraxinus americana; Norway maple, Acer platanoides) were evaluated for 206 d under a range of operating conditions (start-up, steady-state, reducing conditions, and drying-rewetting cycles) for a spectrum of potentially harmful dissolved contaminants. Aerated outflows also were evaluated for acute and chronic toxicity to the biologically sensitive invertebrate Ceriodaphnia dubia. Dissolved metal leaching subsided within the first few weeks of operation, though initial concentrations of copper and zinc were detected at concentrations of concern. Elevated concentrations of tannins-lignin and total ammonia nitrogen were detected throughout the study and were influenced by operational phase. Acute toxicity was not generally detected, though chronic toxicity was observed during drying-rewetting cycles in the maple outflows. The measured toxicity was not correlated with water chemistry, indicating an additive effect of several toxicants. Overall, significant differences in outflow water quality between ash and maple wood species were negligible. Results indicated that bioreactor outflows may be applicable for aquacultural reuse, though reusing outflows immediately following start-up or restarting after a dry period would not be recommended.     

Drag force and reconfiguration of cultivated Saccharina latissima in current

The design of aquaculture systems requires an understanding of the drag forces on cultivated kelp. This study measured the drag on line segments of cultivated Saccharina latissima in a towing tank. The drag on segments of farm line with full kelp bundles and with stipes alone (fronds removed) was measured at tow speeds of 0.10 to 0.50 m/s. The drag on individual fronds cut from the line was also measured. Video images were collected to evaluate the plant reconfiguration. Both kelp blades and stipes contributed to the total drag force on the line bundle. Within the velocity range of our experiments, the kelp blades were essentially horizontal. However, the pronation of kelp stipes increased as flow velocity increased. The reconfiguration of kelp stipes was observed to decrease the vertical extent of the kelp bundle. Due to this reconfiguration, the measured force, $F$, increased with velocity, $U$, at a rate slower than quadratic, and was consistent with scaling laws derived for reconfiguration. Specifically, $F\sim U^{\alpha }$ with $\alpha =1.35\pm 0.17$.     

Bilateral intracorporeally sutured inguinal herniorrhaphy using 3-dimensional laparoscopy in a dog

A 7-month-old, intact male, mixed breed dog with bilateral inguinal hernias underwent general anesthesia for laparoscopic bilateral inguinal herniorrhaphy via a 3-port approach. A 3-dimensional laparoscopic system was used to perform the procedure immediately following prescrotal open castration. Intracorporeal suturing with polypropylene was performed, and 2 cruciate sutures were placed to close each inguinal ring. The caudal aspect of each inguinal ring was left slightly open so as not to disrupt the passage or patency of vessels and nerves. No intra- or post-operative complications occurred. One year after surgery, the dog has no evidence of recurrence of the inguinal hernias.Key clinical message:This case report demonstrates a novel minimally invasive approach to inguinal herniorrhaphy in a dog with no reported complications and a good long-term outcome. Intracorporeally sutured inguinal herniorrhaphy is feasible in dogs with good results, although additional cases are needed to gain experience with this technique in dogs with varying presentations of inguinal hernias.     

Establishment and application of an accurate identification method for fragrant soybeans

In order to screen the aroma characteristics of soybean,a new method was established which can quickly quantify the content of 2-acetyl-1pyrroline (2-AP),an important compound related to soybean aroma,using gas chromatography-mass spectrometry (GC-MS).Based on peak profile,total peak area and retention time as test indexes,an accurate identification method for fragrant soybeans was established.The optimum parameters of the protocol consisted of column temperature70°C,sample injector temperature 180°C,optimum extraction alcohol content 1 m L,Na Cl content 0.1 g,ultrasonication time10 min,and extraction time 1 h,which were established by using the orthogonal test of single factors and three factors with four levels (L_9(3)~4).2-AP content of leaves had significant correlations with seeds,which were easier to measure.The protocol was simple and easy to carry out,consumed only small amounts of reagents,and provided accurate and reliable results with good reproducibility.A total of 101 soybean genotypes from different geographical sources were analyzed using this protocol.The results showed that the average content of 2-AP was 0.29 mg L~(–1),ranging from 0.094 to 1.816 mg L~(–1),and the genetic diversity index was 0.54.Among all genotypes-tested,they were classified into three grades,including seven elite genotypes identified as"grade one fragrant soybeans",which were Zhonglong 608,Heinong 88,Ha13-2958,Hongmiandou,Heinong 82,Huangmaodou,and Jiyu 21.These results provide both an identification technique and several elite aroma genotypes for gene discovery and good quality breeding in soybean.