Improving water management in European catfish recirculating aquaculture systems through catfish-lettuce aquaponics.

In the context of climate change and population growth, aquaculture plays an important role for food security, employment and economic development. Intensive recirculating aquaculture systems (RAS) allow to treat and recycle fish effluents to reduce waste concentration in outflow water thereby reducing environmental contamination. RAS sustainability may be further improved using aquaponics, a circular productive system in which RAS wastewater is recovered for crop cultivation and recycled back to the fish tanks. In this study, water metabolism of a catfish RAS was assessed and the opportunity to produce lettuce with the RAS effluent was tested. Crop growth and water consumption in aquaponics were compared to those experienced in hydroponics at three nutrient solution concentration (EC of 1.6, 2.0 and 3.0 dS∙m-1), also considering water- (WUE) and nitrogen- use efficiency (NUE). A scenario for converting the RAS in a catfish-lettuce aquaponic system was, then, proposed. The RAS water balance included an input of 555 L∙day-1, out of which 32 L∙day-1 were lost by evaporation from the tubs whereas 460 L∙day-1 were discarded. The lettuce yield, NUE and WUE in aquaponics were respectively 20.3%, 22.3% and 20.6% lower than those obtained in hydroponics. Best performances in hydroponics were achieved with EC of 2.0 dS m-1. No difference in term of water consumption arose between the treatments, with average water use of 46 mL∙plant-1∙day-1. Considering the current RAS productivity of 329 kg year-1, a 10 m2 raft system hosting 160 lettuces would satisfy the nitrogen filtration demand. Once closed the water loop between the two productive sub-units, the current water input of 532 L∙day-1 could be reduced to the amount needed to replace the water lost by evaporation (50 L∙day-1) and the RAS water output would decrease from 555 to 103 L∙day-1.

[Esophageal function remains unchanged in systemic sclerosis at four years of follow-up]. / La funzionalità esofagea rimane inalterata nella sclerosi sistematica ad un follow-up di 4 anni.

AIM: Esophageal involvement is one of the earliest gastrointestinal manifestations of systemic sclerosis. Reduced lower esophageal sphincter pressure and reduced esophageal motility can both be measured by manometry. METHODS: 15 patients with systemic sclerosis (6 with altered manometric values and 9 with symptoms of pyrosis and/or dysphagia but with normal manometric values) were reassessed after a follow-up period of over 46 months. RESULTS: Low though still within normal range values in lower esophageal pressure were found on manometry. Distal esophageal amplitude remained substantially unchanged. Only in one patient was the amplitude significantly reduced. In all patients, the symptom scores for pyrosis and dysphagia had worsened slightly. CONCLUSIONS: Esophageal involvement does not necessarily occur in all patients with systemic sclerosis; more time may be required before its manifestations can be assessed by esophageal manometry.

Nizatidine in the short-term treatment of duodenal ulcer--an Italian Multicenter Study.

One hundred and seventy three patients suffering from duodenal ulcer, were selected for a double-blind, controlled and randomized parallel multicenter study, with interval endoscopic examinations. This study was undertaken to compare the efficacy and safety of nizatidine administered at a single dose (300 mg "nocte") versus ranitidine (300 mg "nocte") in the treatment of acute duodenal ulcer. One hundred and sixty five patients were found to meet every admission criterion and completed the study (86 on nizatidine and 79 on ranitidine). On admission to the study, both groups were seen to have been correctly selected and epidemiologically well-distributed as to history of duodenal ulcer, previous treatments and pre-study symptoms. The ulcer was considered healed when complete re-epithelialization had occurred in areas of ulcerated mucosa. Healing rates of duodenal ulcer proved to be globally similar in the two groups, both in the 4th week (nizatidine, 78%; ranitidine, 78%) and in the 8th week (nizatidine, 91%; ranitidine, 95%). After four weeks of treatment, 67% of the patients treated with nizatidine no longer had any symptoms, while 87% patients no longer suffered from day pain, and 91% had no nocturnal pain. As a result, intake of antacids quickly decreased during the first four weeks. A similar response was observed in the group receiving ranitidine. After administration at a single dose of 300 mg in the evening, nizatidine proved to be at least as effective and safe as 300 mg of ranitidine administered in the same way, with respect both to ulcer healing and symptom response.