Structure and dynamics of the shark assemblage off recife, northeastern Brazil

Understanding the ecological factors that regulate elasmobranch abundance in nearshore waters is essential to effectively manage coastal ecosystems and promote conservation. However, little is known about elasmobranch populations in the western South Atlantic Ocean. An 8-year, standardized longline and drumline survey conducted in nearshore waters off Recife, northeastern Brazil, allowed us to describe the shark assemblage and to monitor abundance dynamics using zero-inflated generalized additive models. This region is mostly used by several carcharhinids and one ginglymostomid, but sphyrnids are also present. Blacknose sharks, Carcharhinus acronotus, were mostly mature individuals and declined in abundance throughout the survey, contrasting with nurse sharks, Ginglymostoma cirratum, which proliferated possibly due to this species being prohibited from all harvest since 2004 in this region. Tiger sharks, Galeocerdo cuvier, were mostly juveniles smaller than 200 cm and seem to use nearshore waters off Recife between January and September. No long-term trend in tiger shark abundance was discernible. Spatial distribution was similar in true coastal species (i.e. blacknose and nurse sharks) whereas tiger sharks were most abundant at the middle continental shelf. The sea surface temperature, tidal amplitude, wind direction, water turbidity, and pluviosity were all selected to predict shark abundance off Recife. Interspecific variability in abundance dynamics across spatiotemporal and environmental gradients suggest that the ecological processes regulating shark abundance are generally independent between species, which could add complexity to multi-species fisheries management frameworks. Yet, further research is warranted to ascertain trends at population levels in the South Atlantic Ocean.State Government of Pernambuco, Brazil; Fundacao para a Ciencia e Tecnologia, Portugal [SFRH/BD/37065/2007]info:eu-repo/semantics/publishedVersio

Vitamin D3 Deficiency is Associated with Late-Onset Hypocalcemia After Minimally Invasive Parathyroidectomy in a Vitamin D Borderline Area

BACKGROUND: Concurrent vitamin D(3) deficiency is common in primary hyperparathyroidism (pHPT). We aimed to examine the clinicopathologic features and short-term outcomes of vitamin D(3)-deficient patients after minimally invasive parathyroidectomy (MIP). METHODS: Over 2-year period, 80 consecutive MIP patients had preoperative-fasting 25-hydroxyvitamin D(3) (25OHD(3)) checked. Forty-five patients had a 25OHD(3) level 100 pg/ml (15/57 vs. 0/19, p = 0.013). CONCLUSIONS: Vitamin D(3) deficiency was associated with a higher preoperative PTH level and a greater risk of LOH after MIP. However, the likely cause of LOH remains unclear as both low preoperative vitamin D(3) and high PTH levels could be responsible.link_to_subscribed_fulltex

Total synthesis and isolation of citrinalin and cyclopiamine congeners

It is said that carbon, the most abundant element in organic matter, supplies life’s quantity, whereas nitrogen supplies its quality. It is therefore unsurprising that many natural products that contain basic nitrogens (alkaloids) are coveted for their benefit to human health. However, nitrogen is known to mire many chemical syntheses because of its basicity and susceptibility to oxidation. This challenge may be heightened by the presence of more than one nitrogen atom in a targeted complex alkaloid, but can be met by the selective introduction and removal of functional groups that mitigate basicity, as highlighted herein with the first chemical syntheses of citrinalin B and cyclopiamine B. The chemical connections that have been realized as a result of these syntheses, in addition to the isolation of both 17-hydroxycitrinalin B and citrinalin C through (13)C feeding studies, supports the existence of a common bicyclo[2.2.2]diazaoctane containing biogenetic precursor to these compounds as has been proposed previously