Intensive fishing has not forced dietary change in the South American fur seal Arctophoca (=Arctocephalus) australis off Río de la Plata and adjoining areas

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Computational water stress indices obtained from thermal image analysis of grapevine canopies

Thermal imaging of crop canopies has been proposed more than a decade ago as a sensitive methodology to determine the water status of different crops. This paper describes the development of a semi-automated and automated methodology using MATLAB? programming techniques to analyse the infrared thermal images taking into consideration the pitfalls pointed out previously in the literature. The proposed method was tested in an irrigation reduction and recovery trial for Chardonnay in the 2010–2011 season and in the 2009–2010 season from seven varieties in field conditions. There was a clear separation (assessed by principal component analysis) between control and recovery compared to stress treatments using leaf area index (LAI), stomatal conductance, stem water potential and indices derived from canopy temperatures measured by infrared imaging. High and significant correlations were found between canopy temperature indices and other measures of water stress obtained in the same vines that were independent of LAI. Furthermore, a fully automated analysis method has been proposed using ancillary weather information obtained from the same locations of infrared thermal images. This paper is a first step towards automation of infrared thermography acquisition and analysis in the field for grapevines and other crops.     

Characterization of Isoforms of the Lectin Isolated from the Red Algae Bryothamnion seaforthii and Its Pro-Healing Effect

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.     

Use of the microalga Nannochloropsis occulata in the rearing of newborn longsnout seahorse Hippocampus reidi (Syngnathidae) juveniles

The aim of this study was to evaluate the effect of microalgae on the rearing of newborn juveniles of the longsnout seahorse, Hippocampus reidi. Two treatments in three replicates were tested over a 15‐day period: with and without the addition of the microalgae Nannochloropsis oculata at a concentration of 2.02 ± 0.44 × 10⁶ cells mL^?1. At each replicate, beginning on the second day of life, 120 H. reidi juveniles (stocking density of 3 ind L^?1) were fed the offspring of the benthic copepod Tisbe biminiensis (100 copepod cm^?2) together with newly hatched Artemia nauplii (3.8 mL^?1). From the sixth day of life, enriched Artemia metanauplii replaced newly hatched Artemia nauplii. After 15 days, the H. reidi individuals were counted, measured and weighed. Mean survival was significantly greater in the microalgae treatment (76.42 ± 5.07%) than in the treatment with no microalgae (25.44 ± 6.91%). Moreover, total length, height and dry weight were significantly larger in the microalgae treatment. Thus, the addition of microalgae increases the growth and survival of H. reidi juveniles fed T. biminiensis and Artemia. The higher growth and survival of H. reidi juveniles was not related to the larger ingestion rates but probably to the nutritional improvement of the live feeds or to the probiotic effect. The protocol developed for rearing H. reidi juveniles resulted in a high survival, and represents an advance in the farming of this species.     

High performance liquid chromatography determination of cytochrome P450 1A and 2C activities in bovine liver microsomes

This study reports fluorescence high performance liquid chromatography (HPLC) and UV-Vis HPLC methods for the determination of 7-ethoxyresorufin O-deethylase (EROD) and tolbutamide methylhydroxylase (TMH) activities, respectively, using bovine liver microsomes. The detection limits were 0.022 and 5.5 pmol on the column, respectively; intra-day and inter-day precisions (expressed as relative standard deviation) were <10%. Both methods showed enough sensitivity to allow for an accurate determination of enzyme kinetic parameters according to Michaelis-Menten plots and the results were: K(m)=0.23+/-0.051 microM, V(max)=0.488+/-0.035 nmol/min/mg protein for EROD activity, and K(m)=1010+/-155.7 microM, V(max)=0.089+/-0.006 nmol/min/mg protein for TMH activity. An Eadie-Hofstee plot analysis showed that in bovine liver microsomes, EROD and TMH activities followed a monophasic kinetic pattern. alpha-Naphthoflavone, a cytochrome P450 1A1/2 (CYP1A1/2) inhibitor, and sulfaphenazole, a cytochrome P450 2C9 (CYP2C9) inhibitor, decreased EROD and TMH activities, respectively. The sensitivity of the methods allowed the use of microsomes with low enzyme activity, such as those from veal calf liver. Thus, EROD and TMH activities may be adopted as markers for the evaluation of CYP1A and CYP2C9-like activities in liver microsomes from veal and beef cattle.     

RESEARCH PAPER: Comparison between two methods for cardiac output measurement in propofol‐anesthetized dogs: thermodilution and Doppler

ObjectiveTo compare cardiac output (CO) measured by Doppler echocardiography and thermodilution techniques in spontaneously breathing dogs during continuous infusion of propofol. To do so, CO was obtained using the thermodilution method (CO_TD) and Doppler evaluation of pulmonary flow (CO_DP) and aortic flow (CO_DA).Study designProspective cohort study.AnimalsEight adult dogs weighing 8.3 ± 2.0 kg.MethodsPropofol was used for induction (7.5 ± 1.9 mg kg^?1 IV) followed by a continuous rate infusion at 0.7 mg kg^?1 minute^?1. The animals were positioned in left lateral recumbency on an echocardiography table that allowed for positioning of the transducer at the 3rd and 5th intercostal spaces of the left hemithorax for Doppler evaluation of pulmonary and aortic valves, respectively. CO_DP and CO_DA were calculated from pulmonary and aortic velocity spectra, respectively. A pulmonary artery catheter was inserted via the jugular vein and positioned inside the lumen of the pulmonary artery in order to evaluate CO_TD. The first measurement of CO_TD, CO_DP and CO_DA was performed 30 minutes after beginning continuous infusion (T0) and then at 15‐minute intervals (T15, T30, T45 and T60). Numeric data were submitted to two‐way anova for repeated measurements, Pearson’s correlation coefficient and Bland &; Altman analysis. Data are presented as mean ± SD.ResultsAt T0, CO_TD was lower than CO_DA. CO_DA was higher than CO_TD and CO_DP at T30, T45 and T60. The difference between the CO_TD and CO_DP, when all data were included, was ?0.04 ± 0.22 L minute^?1 and Pearson’s correlation coefficient (r) was 0.86. The difference between the CO_TD and CO_DA was ?0.87 ± 0.54 L minute^?1 and r = 0.69. For CO_TD and CO_DP, the difference was ?0.82 ± 0.59 L minute^?1 and r = 0.61.ConclusionDoppler evaluation of pulmonary flow was a clinically acceptable method for assessing the CO in propofol‐anesthetized dogs.     

Computational Metabolomics Tools Reveal Subarmigerides,Unprecedented Linear Peptides from the Marine Sponge Holobiont Callyspongia subarmigera

A detailed examination of a unique molecular family, restricted to the Callyspongia genus, in a molecular network obtained from an in-house Haplosclerida marine sponge collection (including Haliclona, Callyspongia, Xestospongia, and Petrosia species) led to the discovery of subarmigerides, a series of rare linear peptides from Callyspongia subarmigera, a genus mainly known for polyacetylenes and lipids. The structure of the sole isolated peptide, subarmigeride A (1) was elucidated through extensive 1D and 2D NMR spectroscopy, HRMS/MS, and Marfey’s method to assign its absolute configuration. The putative structures of seven additional linear peptides were proposed by an analysis of their respective MS/MS spectra and a comparison of their fragmentation patterns with the heptapeptide 1. Surprisingly, several structurally related analogues of subarmigeride A (1) occurred in one distinct cluster from the molecular network of the cyanobacteria strains of the Guadeloupe mangroves, suggesting that the true producer of this peptide family might be the microbial sponge-associated community, i.e., the sponge-associated cyanobacteria.     

Comparing three methods to estimate the average size at first maturity: A case study on a Curimatid exhibiting polyphasic growth

The average size at first |maturity (L₅₀) is among the most important parameters for fisheries management and conservation. This paper aims to compare three different methods for its estimation. Considering a classical approach, a logistic model was used (a) by determining the gonadal stage macroscopically; and (b) by using the GSI as proxy of sexual maturity; and finally; (c) by using the length–weight relationship (LWR) in a theoretical approach. The proposed methods were applied using data of a detritivorous fish, Cyphocharax abramoides, monthly sampled using gill nets. Captured individuals were measured, weighed, sexed and the gonadal stage was classified macroscopically and weighed. Estimated L₅₀ values using the macroscopic identification, GSI approach and LWR were not different from each other considering confidence intervals. Between the three different techniques, we concluded that the analysis of the LWR in fishes with polyphasic growth presented promising results as it only requires length and weight data to be performed and estimate a L₅₀ within the range of both classical logistic models analysed.