Evaluating the performance of temporal and spatial early warning statistics of algal blooms.

Regime shifts have large consequences for ecosystems and the services they provide. However, understanding the potential for, causes of, proximity to, and thresholds for regime shifts in nearly all settings is difficult. Generic statistical indicators of resilience have been proposed and studied in a wide range of ecosystems as a method to detect when regime shifts are becoming more likely without direct knowledge of underlying system dynamics or thresholds. These early warning statistics (EWS) have been studied separately but there have been few examples that directly compare temporal and spatial EWS in ecosystem-scale empirical data. To test these methods, we collected high-frequency time series and high-resolution spatial data during a whole-lake fertilization experiment while also monitoring an adjacent reference lake. We calculated two common EWS, standard deviation and autocorrelation, in both time series and spatial data to evaluate their performance prior to the resulting algal bloom. We also applied the quickest detection method to generate binary alarms of resilience change from temporal EWS. One temporal EWS, rolling window standard deviation, provided advanced warning in most variables prior to the bloom, showing trends and between-lake patterns consistent with theory. In contrast, temporal autocorrelation and both measures of spatial EWS (spatial SD, Moran's I) provided little or no warning. By compiling time series data from this and past experiments with and without nutrient additions, we were able to evaluate temporal EWS performance for both constant and changing resilience conditions. True positive alarm rates were 2.5-8.3 times higher for rolling window standard deviation when a lake was being pushed towards a bloom than the rate of false positives when it was not. For rolling window autocorrelation, alarm rates were much lower and no variable had a higher true positive than false positive alarm rate. Our findings suggest temporal EWS provide advanced warning of algal blooms and that this approach could help managers prepare for and/or minimize negative bloom impacts.

[Hand reconstructive surgery secondary to giant cell tumor]. / Cirugía reconstructiva de mano secundario a tumor de células gigantes.

The giant cell tumor of the bone is a neoplastic low grade lesion that usually appears in the epiphyseal or metaphyseal region of the long bones. The lesion is usually solitary and becomes symptomatic when a considerable proportion of the bone has been destroyed. It is thought to represent approximately 19% of the benign bone tumors and 9% of all the primary bone tumors, according to a review by Schajowicz. The treatment of the giant cell tumor is controversial and the literature is confusing. The giant cell tumor is located mainly in the hand. Its potential aggressiveness makes us consider it in the differential diagnosis of the tumor lesions affecting the hand. The proposed treatment should try to preserve function to the extent possible but, at the same time, it needs to be radical enough to prevent a possible relapse. The purpose of this research work is to describe our experience with the treatment of the giant cell tumor in three cases that presented as a lytic, expansive lesion affecting the bones of the hand. They were treated with tumor resection and a bone graft to fill the defect. All three patients had a favorable course.

Iron, zinc, and protein bioavailability proxy measures of meals prepared with nutritionally enhanced beans and maize.

Nutritionally enhanced beans (NEB) with more Fe and Zn than conventional beans (CB) and nutritionally enhanced maize (NEM) with more tryptophan and lysine than conventional maize (CM) were developed as part of a crop-biofortification strategy to improve human nutrition. Proxy measures were used to assess Fe and Zn bioavailability and protein digestibility of a bean recipe (fríjol sancochado) and a maize-milk recipe (mazamorra) prepared with enhanced or conventional crops in Colombia. Fe concentration was similar in the cooked NEB and CB and in NEM and CM (P> or = 0.05); in vitro Fe dialyzability was similar in cooked NEB (9.52%) and CB (9.72%) and greater for NEM (37.01%) than CM (32.24%). Zn concentration was higher in the uncooked and cooked NEB than in the CB (P < 0.05); phytate: Zn molar ratios were high in cooked NEB (36: 1) and CB (47: 1), suggesting low Zn bioavailability, and not different from each other (P = 0.07). There were no differences in Zn concentration or phytate: Zn molar ratio in the maize recipes. Nitrogen, tryptophan, and lysine concentrations were higher in the cooked NEM than CM; nitrogen was higher in the cooked NEB than CB (P < 0.05). In vitro protein digestibility was comparable (82% to 83%) for NEM and CM and higher for NEB (84%) than for CB (82%). The higher nutrient concentrations + similar bioavailability (protein in NEM, Zn in NEB), same nutrient concentrations + higher bioavailability (Fe in NEM) or higher nutrient concentrations + higher bioavailability (protein in NEB) can translate into more nutrients absorbed and utilized by the body.